Yes, LOADINGS is a Scrabble word!

Letter values in Scrabble US: L 1, O 1, A 1, D 2, I 1, N 1, G 2, S 1.

Is it a valid word?

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

weight to be borne or conveyed
a quantity that can be processed or transported at one time
the ratio of the gross weight of an airplane to some factor determining its lift
goods carried by a large vehicle
the labor of putting a load of something on or in a vehicle or ship or container etc.

fill or place a load on
provide (a device) with something necessary
transfer from a storage device to a computer's memory
put (something) on a structure or conveyance
corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones

Also: load up.