Cut a 1/4-inch cap off each tomato. Reserve the caps. Scoop out the seeds and pulp with a tiny spoon or melon-ball scoop. Season each hollowed tomato with salt and pepper. Set aside.
Mash the avocado with a fork in a bowl, add the lemon juice, olive oil, hot pepper sauce, crabmeat, shallots, garlic, and chopped coriander and mix until smooth. Salt and pepper to taste.
Fill each cherry tomato 1/4-inch above the rim with the crab guacamole. Add a coriander leaf for decoration on top and cover each tomato with its cap.