I actually set up a 6' folding table under one half of our 10'x20' EZ-up tent with about 6 folding chairs at the Farmers markets. People seem to love it as they can sit and relax while eating and enjoy our bbq. I would say 80% or more sit down and eat at our table. I also always have extra camping chairs or folding chairs that people use when all the chairs are taken.
James good luck in you catering and vending biz, you will love it.
Kevin:--Cookshack 150, 22.5 WSM, Mobile vending truck, Red Thermopen