Found this on the internet a few years ago and really liked it. Having it today with Brown Sugar Garlic Chicken and a Green Salad. Quantities are enough for 4 people.
1 Red Apple diced
15-20 Seedless Grapes halved (mixed colors work well)
10 New Potatoes cooked and diced
4 tbsp mayonnaise or more to your taste
Mix ingredients and chill before serving