The top bit will be a mix of pork lard & beef tallow and the bottom will be kind of like dripping I guess, made from the cooked meat juices. Is it jelly like?
The top layer will be great for cooking things (e.g. frying eggs, saute'ing veggies, mushrooms etc.), especially as it will be flavoured with the spices and such from your meatloaf. The bottom (if it's jelly like) will revert to liquid when heated and would be good as a sauce or salad dressing
This is what I had left after rendering 2kg of beef fat last night, a bowl of crispy beef crackling and a jar and a bit of tallow:
After cooling for a while the tallow looked like this: