So playing experimental, 11131, and I am getting “Ate like an animal” morale penalties even though I was eating inside an RV sitting on a seat next to a table. (I also had ceramic plate, pewter bowl, spoon and carving fork - but I don’t think those affect anything). According to the flavour text for Rigid Table Manners “Eating without a table and chair frustrates you, but eating like a civilized person gives you a bigger morale bonus.”
I have a save from just before I ate if required for confirmation.