This is MY favorite salad recipe in the entire galaxy. The family likes it too so I always make more than what people think is necessary. Crisp apples drenched in icy cold lemon water to prevent browning then mixed with fresh grapes and veggies straight from the garden. My mouth is drooling already since it's chilling in the fridge as I write this. Be sure to use real mayo, not the non-fat/low fat/artificial stuff. Plan on 1 apple per person. We like the apples unpeeled.
Put the ice, water and lemon juice into a large bowl. Dice the apples (about a 1" dice) and put into the lemon water. It will prevent the diced apple from browning. Swish the apples around then drain and pour into a pretty serving bowl. Don't worry if there is water left on the apples. It will help make the dressing.
Add the celery, red onion, grapes, raisins and walnuts to the bowl with the apples and toss to combine.
Add mayo to the bowl. Start with 1/4 cup and toss. If you need more, add it. 1/2 cup usually is enough but it's up to you.
Cover with plastic wrap and refrigerate until cold. Right before serving, toss again.