Fatty salt pork?! Is it just used for flavor or something?

It is primarily fat, because it's cut from the belly and side of the pig. The main use is just to bring flavor and fat to dishes, which it does quite well. As a rule, you blanch or soak it for a bit to remove excess salt, before adding it into your dish to cook along with whatever. It is going to be fatty, because that's what it is. You can also fry it up into crispy bits, and use the fat to saute things. The bits are wonderful added to cornbread, bread, veggies, you name it. Think of it as a sort of bacon, but without the smoky flavor or sweetness. You don't usually need much to add in flavor, and I'd say your package there should be good for at least 3 different dishes. You can freeze whatever you don't use. Since you already have cooked what you have, you have a few choices. You can slice it and freeze it as is, a few slices in a pack, to add to dishes later on. You can slice and fry it up, and keep the fat to use for multiple dishes, and freeze the crackling bits to add to things. Those can be frozen as well, if you like. Yeah, it is primarily fat- but man, does it bring flavor. If you want more "meat" in the future, when you buy it, look at the packages and choose the one that has more streaky meat. There will never be a lot of lean, though, because of where it comes from.