It probably varies by test center, but usually, there is a room where everyone just throws their stuff. It did not seem very secure though. Putting laptop there might be not advisable.
It’s likely that they offer a room to store stuff. But the way it is handled will probably be different at reach center. You may want to post your location and see if other have been. I took mine on a college campus. They have a room for candidate to leave belongings. There were proctors watching the room. They don’t check the items, so you don’t have to show item by item. I won’t say that 100% secure and I would not leave any thing expensive in plain sight.