I needed to keep one tray cold--the vegetables, dip, and tomato sandwiches. Here's an easy way to chill things without melting ice:
Place a clear Ziploc bac full of ice between two trays. This yard sale relish dish fits almost exactly in my square copper tray. The clear plastic bag doesn't show, but it keeps the ice from leaking out.
You can also use a bowl within a bowl, or a plate atop a shallow bowl of ice.