Put cream cheese and olives into blender container. Cover; blend at high speed until well mixed. Add sherry and Worcestershire sauce. Cover; blend at high speed until smooth.
Add cheddar cheese and seasoned salts. Cover; blend at high speed until smooth. If necessary , stop blender during processing and push ingredients toward blades with rubber spatula. Turn mixture onto aluminum foil or waxed paper.
Refrigerate several hours or overnight. About 30 minutes before serving time, put parsley sprigs into blender container. Cover; blend at medium speed until finely chopped.
Empty onto waxed paper. Shape cheese mixture into ball; roll in parsley to coat competely. Serving suggestion: Serve with crackers or small rye bread slices. Makes one 3-inch ball