Maybe because you were early, the entire dinner wait staff wasn't on duty yet (or they were short staffed) and didn't want to fill up all the tables if they couldn't serve you. Just a thought. Or, maybe they didn't want to seat all the tables in one person's station at one time. It's tough when you wait tables and all of your tables are seated all at once because they all want to order at the same time, they all want their drinks at the same time, etc. Well, that's my theory. I can't see why they would make you wait for the sake of waiting.