For the meatballs: In a small saucepan, combine the sugar with 3 tablespoons water and cook over high heat until a dark brown caramel forms, about 8 minutes. Remove from the heat and add 2 tablespoons cold water, swirling the pot.
In a large mixing bowl, combine the pork, shallot, fish sauce, caramel sauce, and pepper, and marinate in the refrigerator for 1 1⁄2 hours.
For the sauce: Combine fish sauce, vinegar, brown sugar, water, garlic, chile and green papaya in a large mixing bowl. Set aside to marry the flavors
To assemble: Bring a pot of water to a boil and cook the noodles according to the directions on their package. Drain, then rinse under cold water to halt the cooking process.
Shape marinated pork into small patties, about 15 to 20 in all. Heat a charcoal grill or a broiler to high. Grill or broil the pork patties until fully cooked and slightly charred, about 4 minutes per side.
Spoon the sauce into four bowls, then place the pork patties over the sauce. Place the herbs and lettuce in one large communal bowl and the noodles into another large communal bowl. To eat, dip some of the noodles into the sauce and eat with the patties and herbs.