we got back last week, we tried and tried for our trip for an earlier lunch, but the only available time was 3 or so. We walked up at 12 and ask if they had any availability, we're a party of 4 and they did, the people in front of us and the people behind us were also all walk ups as well, this was during "busy" season. The people behind us was a bigger party of 8 and the people in front of us was a party of 2. When we were sitting down waiting there there were other families that were walk ups as well.
We also walk up for Crystal Palace, Cape May Cafe, and Le Cellier. We had reservation at Le Cellier and saw people getting in walking up, so we thought we would do the same later on in the week and they took us in. We couldn't get Crystal Palace either for the trip and we walk in for lunch and breakfast.