I would get there early, tell them you would like to eat outside. They will tell you that they can't guarantee it, but they will note it. They do try, but most people would like to be there if the weather is nice. In April we had 7:30 PS, was there at 7:20, and got seated at 8:40.
Cheese plate, leak and potato soup, fish and chips, and steak and prawns were all very good. OH mmmmmm sticky toffee pudding.