Here's another recipe I saw on the Food Network.
I don't have exact quantities. Do it according to your own taste.
Chop the olives in a food processor or blender. Don't make it smooth. Be sure to leave it a little chunky. Drain the tuna and add the flaky tuna to the olive mixture. Add some capers and a little olive oil. Put in the fridge to let the flavors blend. Serve with crackers, chips, etc.