Combine the main ingredients: In a large mixing bowl, add 3 thinly sliced cucumbers and 1 cubed avocado. Gently toss these together to prevent mashing the avocado.
Add additional ingredients: To the cucumbers and avocado, incorporate 3 tablespoons of corn and 1 julienned red onion. Mix well to distribute the ingredients evenly.
Prepare the dressing: In a separate bowl, whisk together 1 tablespoon low-fat cream cheese, 1 tablespoon mayonnaise, 2 tablespoons lemon juice, 2 tablespoons fresh dill, 1 teaspoon honey, and 1 teaspoon grain mustard. Blend until smooth and creamy. Season with salt and pepper to taste.
Combine the salad and dressing: Drizzle the dressing over the salad. Toss gently to coat all ingredients without squishing the avocado.
Serve or chill: For the best flavor, serve immediately, or refrigerate for about 15-30 minutes to allow the flavors to meld further.