Yeah that's gross. I don't want to see someones dirty feet up on a barstool/chair while I'm eating. Much different if she kept the shoes on while putting them up. Speaking of bad manners...
I've seen (or more appropriately heard) people blow their snot-filled noses at restaurant tables. Several times. Yeah, I get we all do it and people need to blow their nose. But at the table? While everyone around you is eating? Just let me eat my smothered burrito in peace, people!! I don't want to look at the smother sauce and think of your snot!