Okay, there are a couple kinds of hams that you can deal with -
Dry cured - these hams are rubbed externally with a salt mixture, get covered with the salt mixture, which draws out much of the moisture, then are hung to further dry, and are smoked. These are also called "country" hams in the USA, and cured meats like Black Forest hams (Germany), jamon (Spain), prosciutto (Italy) all fall under this category, as well. Since they have such a low moisture content and a lot of the salt is in the meat, you would not receive this as frozen. These arrive in boxes, usually in some kind of a mesh or cloth bag, and can be kept at room temperature until you cook them. They do need to be scrubbed, skin and fat trimmed away, cooked in liquid to partially rehydrate, then cooked, thoroughly. These take a lot more time and effort to make, and their cost reflects that, but the flavor, because of less water content, is very intense. It is fantastic sliced thin after cooled/cold, as well.
Wikipedia - country hams
Most hams eaten in the USA, and ones that you generally buy at a grocery store, are water cured hams. The fact that it was frozen, the appearance, packaging and ingredients list all identify the ham you are asking about as a water cured ham. A saline/sugar/water solution is used to brine the ham.
While you can keep it in the fridge for a while, the brining method used here is more for flavor, not preservation, and those hams will go bad if you just leave them in the fridge for a long period of time.
Here is the USDA site with information about it, along with cooking times -
Ham that - USDA