Preheat oven to 375 degrees F. Wrap taco shells or tortillas in foil; place on a baking sheet. Bake for 5 minutes. Heat bean dip according to directions on can. Meanwhile, stack chicken slices; roll up in a spiral. Cut roll crosswise into eight pieces; use your fingers to shred slightly.
To assemble tacos, spread 1 to 2 tablespoons heated bean dip onto bottom of one of the taco shells (if using); top with lettuce. Add chicken pieces, olives, and cheese. (If using tortillas, place each tortilla on a flat surface; sprinkle ingredients down center. Fold sides over filling.) If desired, serve tacos topped with salsa and sour cream.