Yes, CONTAINER is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, N 1, T 1, A 1, I 1, N 1, E 1, R 1.

Is it a valid word?

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

any object that can be used to hold things (especially a large metal boxlike object of standardized dimensions that can be loaded from one form of transport to another)