Yes, BOOKWORM is a Scrabble word!

Letter values in Scrabble US: B 3, O 1, O 1, K 5, W 4, O 1, R 1, M 3.

Is it a valid word?

BOOKWORM is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a person who pays more attention to formal rules and book learning than they merit
someone who spends a great deal of time reading