Hi Smokestack! The Referee's Manual has an alphabetical list of monsters by area types on pages 112-117. If I wanted Dungeon/Subterranean, I'd break that area list down into hit die groups using Blackadder23's monster list by hit die, then roll depending on what level I needed. For example, you could construct a simple list of ten Level 1s that you like and roll a d10 or, for more challenge variety, maybe drop a Level Two in for slots 8/9 and a Level Three in for slot 10. Most of the time you'd get a "level appropriate" encounter, but once in a while, you'd get something more challenging that might require running away instead of fighting.

Hope that helps and also hope to hear about your campaign in our Campaign forum, whether it's a written or YouTube recap. 

DMPrata wrote:

From the depths of the Black Gulf, your cries have been heard! Random encounter tables for both wilderness encounters and dungeon levels will be included as appendices in the Second Edition hardback.

Well thanks, that's mighty nice of you.  Now I'm looking forward even more to this release!

-SJ