Prep the Cold Sides: Cook the rotini pasta according to package directions, rinse with cold water, and let cool. In a large bowl, toss the pasta with diced bell peppers, black olives, mozzarella balls, beef salami, and beef pepperoni. Cover and refrigerate.
Assemble the Produce: Wash and cut the watermelon, pineapple, carrots, cucumber, and celery. Arrange the fruit (including blueberries and grapes) on one platter, and the vegetables on another next to the ranch dip. Cover and refrigerate.
Set Up the Stations: Arrange the hamburger and hot dog buns, tortilla chips, Frito corn chips, and flavored corn chips in serving bowls. Place the ketchup, mustard, sour cream, guacamole, and salsa in small bowls. Layout the lettuce, sliced tomatoes, onions, pickles, and shredded cheese on a toppings tray.
Fire Up the Grill: Preheat the grill to medium-high heat (about 400°F). Grill the beef patties for 4-5 minutes per side for medium doneness. Add the sliced cheese during the last minute of cooking to melt. Grill the beef hot dogs for 5-7 minutes, turning frequently until slightly charred.
Warm the Chili & Serve: Heat the beef chili in a saucepan over medium heat until simmering. Transfer the grilled meats and warm chili to the buffet table. Let guests assemble their own plates.