We used to do that at camp - on color war day one of the contests was silent lunch, and teams could lose points for talking. It was kind of creepy TBH, but I was in leadership so we just shouted at each other from across the room.

My elementary school had this thing, it was a big traffic light in the lunchroom with what sounded like a sports game buzzer on it. If we were "too loud" they'd blast the buzzer til we got quiet, and we wouldn't be allowed to talk for as long as the light was on red, which usually meant the rest of the lunch period. They pretty much gave us silent lunch every day cause kids are always loud. Idk how that shit was okay lol

Idk what it was like at the beginning of the pandemic, but can confirm, they're not. Everyone is talking like normal. Only thing that stands out is that the tables all have those plastic dividers in the middle and a lot of people put their masks back on once they're done eating, but they'll continue to sit and talk.

Japanese schools do that have lunchrooms afaik, they eat in the classroom.

They don’t have lunchrooms- at least in elementary. They eat in the classroom as far as I know.