Yes, CARAMBOLAS is a Scrabble word!

Letter values in Scrabble US: C 3, A 1, R 1, A 1, M 3, B 3, O 1, L 1, A 1, S 1.

Is it a valid word?

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

East Indian tree bearing deeply ridged yellow-brown fruit
deeply ridged yellow-brown tropical fruit; used raw as a vegetable or in salad or when fully ripe as a dessert

Also: carambola tree, averrhoa carambola, star fruit.