en_tn/num/16/33.md

went down alive into Sheol

A similar phrase occurs in Numbers 16:30. See how you translated it there.

They exclaimed

"They" refers to "All Israel."

The earth may swallow us up also

The people speak of the earth as if it were alive. AT: "The earth might open up and we too will fall into it" or "If the earth opens up again, we too will fall into it and be buried" (See: rc://en/ta/man/translate/figs-metaphor)

fire flashed out from Yahweh and devoured the 250 men

Being destroyed by fire is spoken of as if they were eaten by the fire. AT: "fire flashed out from Yahweh and destroyed the 250 men" (See: rc://en/ta/man/translate/figs-metaphor)

250 men

"two hundred and fifty men" (See: rc://en/ta/man/translate/translate-numbers)