He gets that steak meal from Del Frisco's as a "last meal" for his cellmate he is about to kill. It isn't for him. Men on death row frequently ask for meals similar to the one Clyde requests.
He didn't need the bone from the steak to kill his cellmate or any other silverware they may have given him. He would have killed the dude with or without a weapon.
They purposefully made the cellmate unlikable so that when our anti-hero butchers him, we don't feel so bad for him.