In a bowl, combine ketchup, mayonnaise, and sweet green relish. Mix well and set aside in the fridge until ready to serve.
Heat oven to 350F.
Heat a large heat-proof skillet over medium heat. Add the oil to the skillet and when hot, add the ground beef. Using a wooden spoon, cook the beef, breaking it up as you go, until the beef is half cooked, around 5 minutes.
Add the onions and cook for another minute.
Add the salt, pepper, paprika, garlic powder, and Worcestershire sauce and cook until the beef is cooked through.
Take the skillet off the heat and use your wooden spoon to flatten the beef so it's evenly spread across the skillet. Add the shredded cheese evenly across.
Arrange the tater tots over the cheese in a single layer and transfer the skillet to the oven. Bake for 30 to 45 minutes or until the tater tots are golden and crispy.
Serve with the toppings of your choice and homemade mac sauce.