There are a lot of these. A long time ago on another forum we came up with a pretty good list and ever since, I haven't been able to not make a mental note when I see one in a film that I think would be a good candidate for the list. I have sadly forgotten a lot of these (my mental notes often deteriorate rather quickly) and know that lot of the knowledgeable folks here could come up with some great ones.
Basically, it's any scene in a film that takes place around a dinner table. Usually there are multiple characters present and some sort of awkward hilarity is taking place. Sometimes something horrifying. Lots of times there are family members present and the dynamics involved add to the humor. If you've ever been a guest at someone else's family dinner, it is like getting a glimpse into their own private little world, like a scientist observing a species in its natural habitat. Here are a couple of the more obvious ones off of the top of my head.
I Heart Huckabees...I don't get Mark Wahlberg's bit a lot of times, but he is one of the best things about this somewhat forgettable movie and sells it in this scene that takes place around....a dinner table.
Wedding Crashers....Lots of good things going on here: Vince Vaughn getting a hand job under the table, some old broad railing on Eleanor Roosevelt's lesbianism, Christopher Walken.






