Sidewalk Shuffle can be performed with people behind you. It is a great choice for this venue,but I think the audience has to be able to hear the performer while doing the routine. I know what you mean about the noise in the room. I perform in a Country Club setting and when it's a dinner party the room is very loud, especially when the band is playing. At those times you must perform very visual stuff. Even if you are talking you have to assume that 10 out of 12 people at a 12 top table can't really hear you.

Yep your right Magic Sammy and I think the more visual your effects the better. You can never predict how the enviroment will be, so the more visual material you have on you the better I think.

Cards across with a spectator on the opposite side of the table (while not eating), but a real super visual card trick would be spooked / haunted deck done on the table...(if gimmicks / I*Rs are allowed)
Nestor Hato does a version under a glass dome which looks great on the DVD, but I'm not sure if I'd trust the set up..!