A person’s teeth falling out and landing on the floor, nobody noticing and they have to try to find them by crawling under the table. This happened to a friend of mine.

Somebody letting off a loud and stinky fart. (No I have never done this).

Changing the subject to talk about a gruesome murder of a close friend of the people at a dinner party.

Telling a person at the dinner party that their husband/wife is having a torrid affair.

Larry King had an interesting televised one. I was amazed to see it played out that money and fame really don’t automatically produce stellar specimens of humanity. The current Mrs. King seemed to me the person at the table I would most enjoy talking with. As in most groups, one individual dominates; the atmosphere would change for the positive in any setting this does not occur. Tongue bulging in cheek over use of word amaze!

If two of the people were having and affair and got in a loud argument with the cuckolded person.

A divorce.
A pregnancy.
A marriage proposal.
A lost job.
A death in the family.
A car outside getting towed.
Family dogs humping in sight.
Small children suddenly yakking up.
Toilet clogged & overflowing.
Kitchen or bbq grill fire.
Drunk person taking off all their clothes & walking about.
I’ve never seen any of these.~

Someone comments on how delicious the meat entree is. The host goes into a long, rambling tale about how he hunted and killed the squirrels/pigeons/raccoon himself.

Eating a delicious meat and mushroom pie and one of the guests then regaling the other diners with a story about how recently three of the diners who ate mushroom pie at another dinner party died after it was discovered the chef accidentally used toadstools instead of mushrooms.

Someone loudly hogging the conversation by describing every detail of recent surgery.
Or loudly talking about every detail of a recent golf game and no one else plays golf.

@Sunny2 I have a friend who plays golf and he does exactly that. He doesn’t realise that nobody else is even the slightest bit interested