Tuna salad

Makes about 2 cups

2 5-ounce cans white albacore tuna ( or one bigger can)
2 to 4 tablespoons mayonnaise
1 rib celery, diced small
1 small shallot or 1/4 red onion, diced small
1 tablespoon lemon juice (from 1/2 lemon)
1 tablespoon pickle relish, optional
Salt and pepper