Poor table manners / poor table etiquette bothers me. I am totally put off and lose my appetite if someone is shoveling food, smacking their lips or the worst for me...someone who eats with their mouth open

Also, chewing meat off a bone really bothers me. Worse, when someone sucks on the/a bone after (gag).
Someone that does not utilize their napkin through the meal...uh oh...not appealing.
And finally, I try to be courteous when seeing someone eating alone. I might ask to join them simply to keep them company. Or if we are dining together, when I finish my main dish, I do not leave the table until my companion has finished their meal.
If I am dining out, I pace myself and will not signal the waitstaff that I am done (with my utencils on the plate) until my dining companion is finishing up.
And I feel as though there is always room for a coffee after a meal
(I sound like a dope)