I tend to try to avoid the situation. My wife notices quite quickly these days. Lets go somewhere else, lets take a picnic, MacDonalds anyone.
When I'm in the situation I'm on edge, my hands may shake a little, heart rate goes up. Sometimes halfway through I relax a bit and I'll be fine. Other times I don't.
Familiarity with a place helps. I sometimes have Sunday dinner in a local pub. A large family group of us goes, we sit in the same place (because the group is too large to sit anywhere else) and the food is good. I am fine. I went once with just the wife and kids, the place was full, and we were led to a table in the middle of everyone. I had to leave, I could feel the anxiety building up really quickly.
Does anyone else suffer with this? Not necessarily with food of course.
Thanks for all the advice so far.