The larger rulebook contains more profiles than the Mines of Moria version, which include the basic profiles found in the Mines of Moria rulebook as well as every profile from the following supplements:
Shadow and Flame
The Siege of Gondor
The Battle of the Pelennor Fields
The Scouring of the Shire
However, the other supplements were released after the rulebooks, so their profiles aren't included. The other extra thing that the larger rulebook has is a Hobby section at the back of the book, which contains advice for painting, modelling, building terrain, gaming boards and a fortress (+ a scenario for using your fortress in a siege) and finally some rules for using boats and costal raids in your games.
I hope this helps.