Make the Dressing: In a small bowl, whisk together mayonnaise, lemon juice, salt, and pepper.
Combine Ingredients: In a large bowl, combine apples, celery, grapes, walnuts, and crushed pineapple.
Toss with Dressing: Pour the dressing over the salad ingredients and toss until everything is evenly coated.
Chill and Serve: Refrigerate for at least 30 minutes before serving for flavours to meld. Serve chilled.