There is restaurant outside Genting Casino call 云华宫 (near the lift) is big enough to accommodate more than 100 people, they have big tables too, can try lor. The food quite ok lah and the price is reasonable. We usually (6 paxes) have our dinner there, 5 dishes about RM300-350, 2 vegi dishes, 1 chicken dish, 1 toufu dish and 1 others with 6 bowls of rich and a pot of tea (refillable).
The other 2 restaurants that provide Chinese cuisine hear Maxim hotel, take the escalator up 1 level and you can see the 2 restaurants side by side. 老友记 and 名人. 老友记 is bigger with big tables, 名人 is smaller, they provide about the same types of food, maybe 名人 a little more expensive and better than 老友记.
Other restaurants I tried were either expensive or no big table for 13, unless you are willing to split, can try those at Sky Avenue, so far I tried 阿一小厨, food ok, price very much depend what you eat, a small piece of cod fish is RM120, other than that vegi and chichen/meat are reasonable. Another restaurant I tried, 龙的传人 iDragon, the food not so nice...
Each time I visited Genting, I see long Q outside Lobster and Burger, I haven't got a chance to try because of the long Q. Have to wait 2-3 hours for a meal, I really don't know why people are so willing to wait? Is it really that good!?