Yes, LATTICE is a Scrabble word!

Letter values in Scrabble US: L 1, A 1, T 1, T 1, I 1, C 3, E 1.

Is it a valid word?

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

an arrangement of points or particles or objects in a regular periodic pattern in 2 or 3 dimensions
small opening (like a window in a door) through which business can be transacted
framework consisting of an ornamental design made of strips of wood or metal