From the introduction:
This supplement will help you create fun and memorable dungeon encounters – encounters that your players will love! There is lots of great advice in the Dungeon Masters Guide, but it can take hours to understand and apply it all. We have done all of the hard work for you by pre-generating 300 separate monster encounters, all categorized by level and encounter difficulty, as well as creating dozens of treasure assortments.
We’ve also provided many tables to “spice up” your encounters, covering things such as dungeon architecture, monster actions and general dungeon dressing. In total, there are over 30 tables!
Using this supplement, you will be able to stock a dungeon with awesome encounters in just a few minutes.