Why does ham re-heat so fast in the microwave?
The moisture. A microwave warms the moisture from the inside out.
because of it water content, I think.
Because of all the grease and fat content.
Because it's fatty. And greasy and over all you should warm it up in the oven.
Microwaves vibrate the molecules of liquid to create heat. That's why the glass container doesn't get hot, it's a solid. Ham normally is very moist.
Like everybody's already said, It has water to absorb microwaves.It has fat to retain heat and keep the water from evaporatingIt is small. A single serving of ham is much lighter than a cup of coffee, or a baked potato, etc.