My guess would be a wood handled flat-bladed thingie (scoop?) for picking up sliced brisket and carrying it to the scale for weighing. It's so dark in the room at City Market where you order, I don't remember seeing one, but I know they use something similar at Black's in Lockhart.
Can't really make out a blade on the thing, tho.
BTW, he's slicing, not chopping. Would be a serious foh-paw to ask for chopped brisket at a place like City Market Luling