Whisk the mayo, with the salsa, Tabasco, taco seasoning, and lime juice in a large bowl. Toss in the tuna, mango, onion, pepper, and beans. Season with salt and pepper as needed. Squeeze fresh lime juice on top.
Meanwhile, preheat the grill to medium high. Oil the grate, place the avocado on the hot grill, cut side down, and grill for 5 to 7 minutes, until good grill marks appear and avocado is heated and soft.
Spoon heaping portions of the tuna salad into the avocados and serve.