Few restaurants here have change tables. I've had kids in diapers for nearly 4 years now and have run into situations where we made a call to change the diaper on the floor by our table, or on the bench of the booth if we have a booth. It's a whole lot faster, it isn't messy or dirty as we always have a change pad and most people don't even notice.
Would not try it right on the table though, yech.
Some bathrooms are no good for doing it in there. Dirty or just very poorly setup at all, even for doing on the floor (only floor space is likely traffic area).