You can come out halfway, but there must be something on the table, which means you have to come back.
Note: People usually queue up at 5 o'clock. It doesn't matter if you can't buy a ticket. You can wait at the gate of the study room at the first time (when the door opens at 8 o'clock). If no one comes, arrange the seats where no one comes in the order in which you wait at the door.