Cooking sliced ham to make it tender
You could use pâté or rilette or cretons or similar (spreadable meat pastes). 

Alternatively, Cook's Ham has a recipe for "ham pâté" (Basically throw the ham in a food processor, then mix in some mayo and stuff to make a spread). 

If you're using a city ham (rather than a country ham), it is likely pre-cooked (see the package directions) and all you need to do is re-heat it. If you do this gently (low and slow), you should be able to get better texture. For example, put it in the oven for the lowest oven setting possible until it comes up to temperature (you can add some water / use a turkey roasting bag as well to help), or stick it in a sous vide water bath.