There's also a class of restaurant where you order at a counter, typically are given a flag with a number or whatever, and someone brings the food to your table when it's ready. In general, there isn't tipping in those situations either.

Not working at such a restaurant and given the prevalence of credit cards it's hard to be certain, and in any case it's anecdotal and not structured, but tipping seems that common (at least moreso than in fast food) in that type (fast casual) restaurant.

I suspect that, as well as the bills being smaller, the average tip percentage is smaller than at full-service restaurants.