DCS titles have huge amounts of default keybindings to expose all the functionality of the aircrafts to your fingertips, and not just your mouse pointer. A while ago, I created some reference charts using Emacs key notation. As I started to heavily customise my keybindings since then, they might be somewhat outdated, so use them with caution.
Hopefully, I will find time to update these tables once DCS World 2 comes out. In the mean time, note that you can also export a key bindings reference in HTML directly from the DCS input options dialogue, which is all the more useful if you start to customise them, which I encourage you to do, especially since keybinding customisation are more robustly handled when updating DCS.
You can find the Common Lisp code used to generate these files in a GitHub project.