Mix together olives, giardiniera, garlic, celery, red peppers, parsley, oregano, red pepper flakes, red wine vinegar and olive oil. Cover with plastic wrap; refrigerate at least a few hours, preferably overnight to let flavors blend.
Cut bread loaf in half from side to side, not top to bottom. Spread a layer of olive tapenade on the inside of each half. Layer slices of mortadella, Swiss, salami, provolone and ham on top of bottom half of loaf. Cover with top half of loaf. Cut into fourths and enjoy!