Lay out the 12 bottom halves of the slider buns on a large cutting board or work surface. Spread half of the mayo mixture over the buns - just a small spoonful per bun.
Layer the meat and cheeses evenly on top of the slider buns in this order: pepperoni, Swiss, ham, provolone, roast beef, cheddar, salami and bacon. Fold the meats in quarters so that everything will stack evenly on top of each other. You will only use 1/4 slice of cheese per slider.
Top the meat & cheese with a sliced tomato, a pickle chip & 1-2 spinach leaves.
Spread the remaining mayo mixture on the top slider buns & the add to the sliders. Secure with large toothpicks if needed.
Serve immediately with your favorite potato chips.
Store leftovers in the fridge.