The reviews of the (budget) Pollock Hall accommodation describe its (included) breakfast as 'full Scottish', 'enough to feed the red army', 'all you can eat', etc. So the information below is for later in the day since, even during the Camp Smalltalk weekend, it sounds like you won't need to find food for some time after breakfast. :-)
Edinburgh has, of course, many food shops and supermarkets. Close to the University Central area, good options include a Sainsbury's on the path to the Meadows.
Edinburgh has many good restaurants in the centre and in main residential areas. Most open until 23:00 or midnight. Many offer much cheaper "pre-theatre" menus in the early evening (usually before 19.00/19.30).
Pubs also often offer food at reasonable prices, but menu options can be limited, and quality can vary. Pubs, pizzerias and ethnic (Indian, Chinese) restaurants often offer the best value (there is also a budget section below for anyone really counting the pennies). Italian restaurants can be relatively expensive and are often uninspiring. Note that while most restaurants will sell bottled water, tap water is perfectly safe to drink and very pure. Restaurants will supply it free if you ask for it.
If you are travelling into the Highlands or Islands, note that restaurants often close much earlier than in the city (sometimes 20:00 or so in remote parts!), generally don't offer the same range of options, and are usually a little more expensive than a city equivalent (reflecting high transport costs). Again, most pubs will offer some food options.
Our google map shows most of the following recommended restaurants and some other key points of interest.
Restaurants are listed below by category: some appear in more than one.
Kalpna, 2-3 St Patrick Square, EH8 9EZ, Tel: 0131 667 9890: South Indian wholefood vegetarian, about £15-25
Ann Purna, 45 St Patrick's Square, EH8 9ET, Tel: 0131 662 1807: Similar concept to the Kalpna, slightly cheaper, with different menu options
Mother India's Café, 3-5 Infirmary Street, EH1 1LT, Tel: 0131 524 9801: First rate Indian "tapas". Big tables so good for groups.
Khushi's Diner 32b West Nicolson St, EH8 9DD, Tel: 0131 667 4871: Punjabi restaurant, good range, with some less usual choices for an Indian restaurant, about £10-20, BYOB (no corkage charge).
The Khukuri 8 West Maitland Street, Tel: 0131 228 2085: Prize-winning Nepalese restaurant, with some uniquely Nepalese dishes, near Haymarket station, £10-15
Roti 73 Morrison Street, Tel: 0131 221 9998: Stylish Indian restaurant with unusual menu choices, including Haggis Samosas, and a tiffin menu. 20% discount during the festival using the online voucher. £20-25
Hanam's, 3 Johnston Terrace, Tel: 0131 225 1329: Good quality Kurdish and Middle-Eastern restaurant, near the castle, about £10-15
Nargile, 73 Hanover St, Tel: 0131 225 5755: Excellent Turkish restaurant, friendly welcoming staff. Good choice of meze.
The Olive Branch 44-46 George IV Bridge, Tel: 0131 226 4155: Mediterranean food by an up and coming chef. Deli upstairs, seating downstairs in the vaulted warehouse.
Muang Thai, 97 Hanover St, EH2 1DJ, Tel: 0131 220 6119: Centrally located Thai restaurant. Good, tasty Thai food, about £15-20
Thai Orchid 5a Johnston Terrace, Tel: 0131 225 6633: Excellent Thai restaurant making good use of fresh ingredients, no MSG, near the castle £15-25
La Petite Folie 61 Frederick St, EH2 1LH, Tel: 0131 225 7983: Consistently highly rated, about £21 plus wine
La Garrigue 31 Jeffrey St, EH1 1DH, Tel: 0131 557 30: Very well-regarded Languedoc restaurant, about £30
Ristorante Al Dente, 139 Easter Rd, EH6 8HU, Tel: 0131 652 1932: This out of the way Italian is one of the city's best and above the usual standard. Small, so book ahead. About £15-20
Amore Dogs,104 Hanover Street, EH2 1DR, Tel: 0131 220 5155. Tasty, reasonably priced Italian food in a central location. Light, airy restaurant. Fast service. £10-20.
Viva Mexico, 41 Cockburn St, EH1 1BS, Tel: 0131 226 5145: Edinburgh's first Mexican restaurant. Decent meal for under £20.
Mariachi, 7 Victoria Street, EH1, Tel: 0131 623 0077: Voted the best Mexican restaurant in Edinburgh
Pancho Villa's 240 Canongate, EH8 8AB, Tel: 0131 557 4416: Reasonably priced, good portions, centrally located, can be crowded at weekends, otherwise quiet.
Iggs, 15-19 Jeffrey St, EH1 1DR, Tel: 0131 557 8184: Authentic Spanish restaurant, with good selection of tapas, paella etc., excellent Spanish wine list, about £15-20 plus wine
Cafe Andaluz, 77 George Street, EH2 3EE, Tel: 0131 220 9980: Lovely Spanish tiling. Good tapas and paella menu. £12-25.
There are several good fish restaurants in the Leith Waterfront area. Take a bus or taxi (10-15 minute ride)
Café Royal Oyster Bar, 17a W. Register St, EH2 2AA, Tel: 0131 556 1884: 140 year old seafood restaurant, one of the few in central Edinburgh, about £25
Fishers Bistro, 1 The Shore, Leith, EH6 6QW, Tel: 0131 554 5666: One of Edinburgh's finest fish restaurants
Fishers in the City, 58 Thistle Street, EH2 1EN, Tel: 0131 225 5109: A branch of Fishers in the city centre, generous portions, quiet area at the back
Skippers Bistro, 1a Dock Place, Leith, Tel: 0131 554 1018: Small, intimate and very popular. Book ahead.
The Shore, 3-4 The Shore, EH6 6QW, Tel: 0131 553 5080: Less expensive than Fishers or Skippers, but still good
No. 1 Sushi Bar, 37 Home Street, EH3 9JP, Tel: 0131 229 6880: Good sushi, something of a rarity in Edinburgh. Located in Tollcross
A Room in the Town, 18 Howe St, Tel: 0131 225 8204: Good cooking, consistently well rated, optional bring your own wine (£3-4 corkage charge), about £20-25 (also has a second branch - called A Room in the West End, a little west of Princes Street)
Hotel du Vin, 11 Bristo Place, EH1 1EZ, Tel: 0131 247 4900: Quality bistro-style dining, £20-30 plus wine.
The Witchery, The Royal Mile, EH1 2NF, Tel: 0131 225 5613: Unbeatable surroundings and ambiance, £30-50 plus wine.
The Tower, Chambers St, EH1 1JF, Tel: 0131 225 3003: gourmet dining in the Museum of Scotland, spectacular views of Edinburgh castle, £30-50 plus wine.
Oloroso, 33 Castle Street, EH2 3DN, Tel: 0131 226 7614: Contemporary cuisine with panoramic views across the New Town and Edinburgh castle.
Number One, Balmoral Hotel, Princes St., Tel: 0131 557 6727: Michelin-Starred Restaurant in a large hotel by Waverley staton, around £60 plus wine.
Plumed Horse, 50-54 Henderson Street, Leith, Tel: 0131 554 5556: Rave reviews, Michelin-Starred.
Martin Wishart, 54 Shore, Leith, Tel: 0131 553 3557: Seafood, highly regarded, Michelin-Starred.
The Atrium, 10 Cambridge Street, EH1 2ED, Tel: 0131 228 8882: "Cutting edge" cuisine with an excellent wine list, £25-40 plus wine, but mixed reviews.
Kublai Khan, 43 Assembly Street, Leith, EH6 7 BQ, Tel: 0131 555 0005: Mongolian barbeque, WILD BOAR, OSTRICH, SHARK, VENISON, SPRINGBOK, KANGAROO, and ZEBRA plus conventional meat/veg! £21-23 for the Mongolian Feast; pre-theatre menu available up to 19:00. Take a bus or taxi from the centre.
The Elephant House, George IV Bridge, EH1 1EN, Tel: 0131-220-5355: J.K. Rowling is said to have written Harry Potter here. Good views from the picture window to the Castle. Evening meals available.
always Sunday, 170 High St, EH1 1QS, Tel: 0131 622 0667: Bright modern non-chain café on the royal mile. Open 08:00-22:00 (09:00-22:00 Sat/Sun). Coffee, smoothies, cakes, and light meals.
Valvona and Crolla Caffè Bar, 19 Elm Row, Leith Walk, EH7 4AA: Café in one of the UK's best Italian Deli's, open in the evening during the Festival
Mamma's Pizza & Panzeroti, 30 Grassmarket, Tel: 0131 225 6464: Excellent non-chain pizza with generous toppings.
Pizza Hut, 34-36 Hanover Street, EH2 2DR: International chain, consistent but basic, about £10-20
Pizza Express, 23 Northbridge, EH1 1SB: Decent chain of pizza restaurants, better options than Pizza Hut, but more expensive, about £20
The Standing Order, 62-66 George St, EH2 2LR: Part of the JD Wetherspoon chain (one of three in the city). Cheap breakfasts and coffee, good value pub food, cheap (and good) beer and free wifi in a large Grade A listed building, main meals from £2.99
The Baked Potato Shop, 56 Cockburn St, EH1 1PB: Filling, cheap (£3.50), but tasty baked potatoes, only vegetarian/vegan, very restricted seating (mainly takeaway)
Pie Maker, 38 South Bridge, EH1 1LL: wide range of pies at £1-2, many vegetarian/vegan optons, some window seating
The Tailend Fish & Chip Shop, 14-15 Albert Place, Leith Walk: "The best fish and chips in Edinburgh", about £7 take away, £14 sit-in, 15-20 mins from city centre
McDonalds, 137-138 Princes St, EH2 4BL: Central, large, but can get busy, universally known menu
There are also numerous "fish and chip" shops (traditional British fast food, fried in batter), snack bars/cafes, kebab shops, and street vendors around the city, as well as national/international burger chains and Kentucky Fried Chicken. There are several inexpensive sandwich and takeaway outlets at Waverley station, including a "Pasty" shop.
Almost all restaurants will have at least one vegetarian option; Indian, Italian and Pizza restaurants are always good choices for vegetarians. Vegan options can be harder (Indian restaurants can be a good choice, but curry sauces and breads may contain milk products, so do ask if in doubt). Most of the following have decent vegan ranges as well as catering to vegetarians.
Kalpna, 2-3 St Patrick Square, EH8 9EZ, Tel: 0131 667 9890: South Indian wholefood vegetarian, good quality food, about £15-25
Ann Purna, 45 St Patrick's Square, EH8 9ET, Tel: 0131 662 1807: Similar to Kalpna, slightly cheaper and preferred by some, with different menu options, about £15-20
Hendersons Salad Bar, 94 Hanover St, EH2 1DR: Vegetarian whole-food cafe, several vegan options; about £8-12
Roti, 73 Morrison Street, Tel: 0131 221 9998: Stylish Indian restaurant with some unusual menu choices, including tasty vegetarian options. 20% discount during the festival using the online voucher. £20-25
Black Bo's, 57-61 Blackfriar's Street, Edinburgh, EH1 1NB, Tel: 031 557 6136: Quality vegetarian dining, about £30
David Bann, 56-58 St Mary's Street, EH1 1SX, Tel: 0131 556 5888: Very good vegetarian restaurant, about £15-20
L'Artichaut, Eire Place: vegetarian restaurant offshoot of Jean-Michel Gauffre's La Garrigue restaurant, promising gourmet vegetarian dining with a very slight French twist.
Hanam's, 3 Johnston Terrace, Tel: 013 225 1329: Good quality Kurdish and Middle-Eastern restaurant, several tasty vegetarian options, near the castle, about £10-15
Khushi's Diner, 32b West Nicolson Street, , EH8 9DD, Tel: 0131 667 4871: Good vegetarian range, with some unusual choices, £10-20, BYOB (no corkage charge).
Thai Orchid, 5a Johnston Terrace, Tel: 0131 225 6633: Good range of vegetarian choices for a Thai restaurant
Pie Maker, 38 South Bridge, EH1 1LL: Budget pie/pasty shop. Wide range of pies at £1-2, many vegetarian/vegan, some window seating.
The Baked Potato Shop, 56 Cockburn St, EH1 1PB: Filling, cheap (£3.50), but tasty baked potatoes, vegetarian and many vegan fillings, very restricted seating (mainly takeaway)
The Engine Shed, 19 St Leonard's Lane, EH8 9SH, by Arthur's Seat, fresh bakery goods, excellent affordable vegetarian/vegan food, but only open 10.00-15.30 Mon-Sat
Many restaurants will offer to make gluten-free dishes (or adapt menu items), as long as you ask, but choices may be restricted. Usually Indian or vegetarian restaurants (Annpurna, Black Bo's) are good choices - vegetarian places tend to be used to gluten free options. The following are known to offer good options (recommended by someone who is gluten intolerant):
Hendersons Salad Bar, 94 Hanover St, EH2 1DR: Vegetarian whole-food, several vegan options; about £8-12
Several Italian restaurants have gluten-free options now (Giulianos, La Favorita, Vittoria on Leith Walk).
Cafe Andaluz on George Street (Spanish tapas) marks a lot of their items as "GF" for gluten-free.
Blonde and The Outsider also have good gluten-free options.
The Falko Konditormeister bakery, 185 Bruntsfield Place, Edinburgh, EH10 4DG¿, Tel: 0131 656 0763:¿ often has gluten-free cakes too.
Kushi's Diner, 32b West Nicolson Street, EH8 9DD, Tel: 0131 667 487: Punjabi restaurant, good range, with some unusual choices, fully halal £10-20, BYOB (no corkage charge).
Hanam's, 3 Johnston Terrace, Tel: 013 225 1329: Good quality Kurdish and Middle-Eastern restaurant, several halal options, near the castle, about £10-15
Edinburgh doesn't have a large Jewish community and I'm not aware of any specifically kosher restaurants, but some restaurants (e.g. the Ann Purna) will be able to rise to the challenge, if asked.
The Falko Konditormeister bakery, 185 Bruntsfield Place, Edinburgh, EH10 4DG¿, Tel: 0131 656 0763:¿ makes challah bread, especially for the Jewish community, that can be bought on a Thursday or Friday
Most restaurants will be aware of nut allergies; many menus will indicate which items are nut free, and restaurants will often adapt dishes to suit. Some menus will warn that dishes may contain traces of nuts. Other special dietary requirements can normally be discussed with the waiter/chef.
Edinburgh has a large number of pubs and bars. Many of them will open late during the Festival (it is allegedly possible to drink 23 hours of the day if you're so inclined!), and many have interesting decoration or historical connections. Pubs will often serve food/snacks as well as drinks.
Many cafes and pubs will offer wifi connections. The Rose St. Brewery in Rose St offers free wifi for its customers, and the Standing Order in George St also offers 30 minutes free wifi.
All Scottish pubs, bars and restaurants are obliged to ban smoking in all indoor locations (since 2007). Many restaurants and pubs have outside seating areas, often with heating (there are several in George St).
The List restaurant guide Comprehensive guide to the capital's restaurants
Tim Day/Julie Odell's guide Useful comments and ratings
Ian Sommerville's guide Detailed comments and ratings by a Scottish informatician
Some suggestions from G. Steel.