I mostly play Pathfinder and 5e D&D, but if asked, I do also consider myself an AD&D 2nd edition player. In fact, emotionally I consider 2nd edition "my edition" because it for that edition I rolled my first characters (which I then never played, because my parents forbade it), and I read Dragonlance novels without knowing they were related to 2nd edition AD&D, and it was 2nd edition Planescape that my girlfriend at the time used to introduce me properly to the world of D&D.
When I play now, I use my 2nd edition rulebooks (I allow my players to use the phenomenal clone Swords & Wizardry rulebook if they want to.) I only use my rulebooks because I happen to have them as sturdy physical books, and I'm pretty used to where everything is. But even when I know the page number of a table, sometimes all I really want is a single convenient location to look for a quick answer.
Traditionally, of course, this problem was solved with a DM screen. With COVID-19 forcing me to play the bulk of my D&D games online, a DM screen feels inconvenient (would it go behind my keyboard? off to the side? would it block my view of my monitor?) Instead, I've taken to placing important information in the inside front and back covers of my game books. Sometimes I use a marker (the 5e books have black paper lining the covers, so I have to use a silver marker), and other times I just print out tables and glue them in. It's an instant DM screen that I only have to have in front of me when I need it.
Unlike 1st edition, you can get through a lot of a 2nd edition game without consulting tables. Eventually, players learn their THAC0, they know their own bend bars and lift gate percentages, and you know monster THAC0 by hit dice. Personally, I also provide players with their spell save values, which is in the DMG but I've always felt ought to be in the PHB. This makes game play feel more like a game and less like an exercise in library science, but it's nice to have the common stuff available for quick verification.
Here's what I've pasted into the front cover of my 2nd edition rulebook:
In my Dragonlance Adventures book, I include these:
As I've already done the typing and layout (such as it is), I figured I'd post them here in case you want a copy for yourself.
It's nothing fancy.
It's just some tables in LibreOffice, but at least you don't have to replicate the work (or it's a good start if you're determined to replicate the entire attack tables.)
To extract the bundle, you may need to download and install the free and open source 7-zip archive tool (that's
p7zip for Linux users, available from your software repository).
To open the file, you must have LibreOffice (I use this instead of, for instance, Microsoft Office) or any word processor that reads