If I were to ask for salt for chips in a cafe or something, no problem. But in a proper restaurant, that would be the same as what @ScrollinMyDayAway describes: it would mark me as some kind of philistine that can’t appreciate the chef.
I’m fascinated by this stuff too! We share a language and consume a lot of your pop culture but there are still so many little things that are different.
Eg “tuna noodle casserole” sounded super gross to me because of the language difference. Here, casserole = a thin, liquid stew with chunks of meat in it, cooked in a ceramic pot, and noodles = only Asian noodles (ramen, udon, etc). But it turns out it’s more like what we call a “pasta bake”, a totally normal dish.