We are taking our vintage travel trailer to a rally this weekend. There is a potluck Saturday night and I need to do better than last year, when I took hummus and pita chips from TJ's. Any kind of dish is fine (appetizer, main, or dessert) but I need to be able to make it with no oven, limited refrigeration (an old-fashioned icebox), and on a picnic table since my tiny trailer has no counter space. We are leaving Thursday so I can't really make too much ahead. Any and all ideas/suggestions are very much appreciated! Thank you!