Wash and core the apples, then chop them into bite-sized pieces.
Halve the grapes and remove any seeds.
Dice the celery into small pieces.
Chop the walnuts into coarse pieces.
In a large bowl, combine the apples, grapes, celery, and walnuts.
In a separate bowl, mix the mayonnaise and lemon juice until smooth.
Pour the dressing over the fruit mixture and stir gently to combine.
Add salt and pepper to taste, and honey if desired.
Chill the salad in the refrigerator for at least 30 minutes before serving.
Serve on a bed of lettuce.