One of E's colleagues took us out to a Vietnamese dinner a couple of weeks ago.
These were half of the leftovers with which we were sent home:
Culturally, it was clear something was going on. The feast to feed 25 when there were 6 of us at the table? No idea what it was, but it was clearly something, culturally. I just tried to make it clear that we were very grateful and that we were enjoying ourselves (and I was -- it was the best Vietnamese meal I've ever had in my life, by an order of magnitude, even if I was stuffed before we were 1/3 through).
Bonus -- the leftovers made for a wonderful lunch and a great seafood soup base for dinner with a friend a few days later.