its fine to go to Plaza Gardens for lunch or dinner without a reservation, especially if you're going for late lunch or early dinner. When we were there in November it was closing at around 5.30pm when the park closed at 7pm. But it was open right through from around noon until then. We've eaten there at around 1pm in the past, and also at around 4.30pm, and it was lovely both times, lots of choice and hot. At 4.30pm last March the restaurant was very quiet .