Apparently these are for French onion soup! Which I learned when I asked if it was oven safe and three different people were like “Oh, the bowls for onion soup. French onion soup bowls. One made purposefully for French onion soup under a broiler” and I felt very silly, but now I know they’re oven safe!
They’re cute little things!
I got French onion soup bowls from Costco. They turned out not to be oven safe.
You’ve got vintage ones like we had growing up, though, so they should be fine.