For more drama set in mundane cafeterias, I just remembered this scene from Mike Leigh´s
Secrets and Lies:-
Hortense is a young, adopted, black woman. Because of the recent death of her adoptive mother, she is now searching for her birth mother. By phone, she arranges to meet Cyththia Purley outside a London tube station. When they meet, Cynthia is confused, but trying to be helpful, she agrees to go for a cup of tea with Hortense to talk about her search ....
I put the spoiler tags because it´s a key scene from the movie, and you may want to get yourself a handkerchief before you click to witness Brenda Blethyn´s performance.