Hmmm... it's not all that long ago that 1200x800 was considered a pretty decent screen size. I have an old Samsung netbook with a 1024x600 screen, and yes, it runs Windows 10. Some spaced out GUIs are unusable on this size of screen, with vital buttons being inconveniently off screen, but most things are OK. Powershell is no problem at all. The default window doesn't even fill the screen. If your pixels are too small you can increase the font size. You'll be running a trivial command (or calling a canned script) so a command window with just a handful of lines will do fine - the traditional 80x24 character cell window is far more than you need.
If all you are doing is issuing simple commands like "adjust time 3 seconds forward" there's nothing you need to read.
I don't see how it can be any harder than reading the datamode application that you brought the tablet for in the first place.