Most any of the seafood selections (skip the breading and sauces), low carb veggies (broccoli, green beans, cauliflower, etc...), salad.
I believe they also have baked or broiled chicken and steak on the menu.
Basically, avoid breading, sauces and those cheese biscuits they put on the table and you should be fine.
Watch out as well for the tartar sauce (often has sugar) and cocktail sauce (always has sugar and is high in carbs for a small amount). Drawn butter would be a good choice for pouring over or dipping the seafood in.