At chef Mickey's they have a napkin dance where the characters dance and wave napkins to a song, and you wave your napkin too, but you don't get up.
At Crystal Palace, the characters lead a parade of kids around the room. Same at Ohanna breakfast.
We've never had a problem missing one of these events, and at Chef Mickey's, sometimes they've done it twice while we are there.
Most meals usually last around an hour, maybe less.
Often, a handler will stop by your table to ask if each character has stopped by. If someone hasn't, tell them and they will make sure they do. Usually at CP, the server will fill us in as we are seated, about the path the characters usually take, so we have an idea when they will be by.
At buffets, we are usually warned to watch the character's path and if they are headed our way, don't get up and get in the buffet line, because you may miss the character and it's 40 minutes before they come around to your table again.