Albacore Tuna with Celery and Walnuts

4 ounces premium tuna, such as Ortiz, drained

2 tablespoons chopped capers

2 tablespoons very finely diced celery

2 tablespoons chopped toasted walnuts

2 teaspoons olive oil

1 tablespoon red wine vinegar

1 teaspoon finely minced nicoise olives

1 teaspoon finely minced fresh parsley

1/2 teaspoon lemon juice 

Kosher salt and freshly cracked black pepper

12 butter crackers, such as Ritz