Keeping Food Cold for the Dinner Table

When I have to put out dinner and don't want to refrigerate the bowl of sliced fruit, for example, because there isn't enough room in the fridge, I do this. I will put the fruit in a bowl, cover it with a Corelle plate and put as many small freezer packs (blue ice for lunchboxes) as will fit on the top of the plate.

Keeps it cold enough to last while I prepare the rest of dinner. It's good for at least an hour. I don't know if this would work with a mayonnaise based product, but based on the theory that heat rises and cold falls, the fruit seems to be remaining tolerably cold until meal time.

We have a special shelf in the freezer just for the little blue ices. Been doing this for a couple of years and am satisfied with the results. I got the idea from the Chillzane platters. However, I was wondering how they could keep the food cold enough since the cold radiates downward, rather than upward to the surface of the plate. I would have purchased one of those platters, but they need to be hand washed and I prefer to use a dishwasher (seems more sanitary).