When people aren't sure if they want to see magic, I generally offer to show 1 effect and they can then see more if they want or I can not, it's up to them. It's hard for me to understand exactly what the problem is because all you really said was "Tonight I had a table that just didn't respond." that could mean a number of things, you might want to get into more detail about how they reacted. It could have meant that they didn't know how to respond because they've never had a stranger come up to them and ask them to see magic during dinner. I know if a stranger walked up to me and asked if they could entertain me, I'd hesitate.
magicdude this is a great post!
I am gonna ellaborate a bit more. people often act strangly twards the magician because they dont know how else to respond. I mean if you think about it its kind of a strange request hey can I show you some MAGIC!!! well any way the best way to deal with this is just how magic dude said give them a breif demo so 99% of the time they will immidiatly get use to you and start acting less cold. but in the case of the other 1% they usually are not interested in seeing anything and you should probably book it, one or two tricks into your routine. its usually better to avoid these tables all togeather. there are some simple signs that will help you know if a table or group actually wants to see magic.
1. if they are dressed nicly and talking buisness you can probably bet they dont want to be inturrupted. inless they request it.
2.if they are having a long conversation and not laughing or joking at all thats another sure fire sign.
you usually want to look for people who seem to be enjoying them selves, before the meal not people in the middle of there meal, or people who are having a serious talk. obviously you wont always know if somone does or does not want to see magic, so somtimes its polite to ask if they seem to be talking about somthing serious, say somthing simple like might i interupt for a minute? somthing along those lines.