ScummVM is available for Android. I think there is an on-screen keyboard. A lot of games (full list below) worked well including Sam & Max, Monkey Island, Day of the Tentacle, Full Throttle, Space Quest, etc, through to 3D games like The 7th Guest:-
https://www.scummvm.org/compatibility/

As for tablets I don't keep up with the newest ones for recommendations and have never owned a Windows tablet. Not all keyboard & mouse DOS games in general will translate well to a touch-screen, especially if the game contains things like "edge-scrolling" (using a mouse) which is hard to replicate on a touch-screen without accidentally clicking at the screen edges, or 3D games with a lot of controls like Descent. And FPS's like Doom, I've found never really play well using touch-screen controls. They're generally best for 2D adventure / puzzle games.

That's what I'll mainly be playing, adventure games

Been wanting to get a windows tablet and turn it into a DOSBox machine for some old games. wonder if you can put android esk controls on the screen when playing them or you need a wireless keyboard and mouse?

I play a lot of games on a Windows tablet but nothing that old. Usually the game itself or the platform (emulator) has to be coded for touch screen, wich rarelly is on Windows. I believe Android should be better suited for that task.

A few years ago came across a "no brand" tablet awsome deal and is the better purchase I did in a lot of time. My model has a detachable keyboard/touchpad and is really hepfull, most of the time I tend to use it as a touch screen laptop, not a standalone tablet due Windows inadequacy to deal with touch devices. Last Win10 versions are getting better and is possible to use touch only with the on-screen touchpad.

There are some games wich control as in Android, like Trine2, Grid or the awsome PPSSPP emulator, yes you can play your PSP library with touch only! My tablet version CPU is the Atom x5 z8350, wich is only capable to emulate 2D or "weak" 3D games though. Still a lot of good PSP games to play, like castlevania, FF tactics, Loco Roco etc...

If you don't mind checking Steam, here is a curator looooong list of touch supported games, some are pretty good: (it misses a few games though, Shadowrun Returns or Dungeon of Hell...)

I also played games on a Windows pro tablet (pro meaning you can install any app just like normal Windows and not limited to the Microsoft store.) I Played SQ4 and completed it via DosBox and it worked very well. I also tried Torchlight 1 and it ran ok it was jerky in some spots and very slow during very action packed areas. I used an on the GO cable and a wired mouse and a wireless Bluetooth keyboard and I had a nice setup and it a very good job. An on the go cable allows you to convert the charging port to a standard USB port if your tablet is lacking USB ports. Never tried using the touch screen aspect for games though.

If it's all left-click-based point-and-click with no timed sequences and such, it works kind of nicely.

Your comfort level will drop if the original game had something like right clicking to access some functions, or any timed/arcade sequences which might require very accurate controlling.

Games like old Sierra games with parser input and sudden deaths are easy to get running on tablets, but almost impossible to play.

So it all depends on what you are trying to play, and how much time you are willing to invest in trying to overcome control issues which have been designed for mouse+keyboard, and don't work as intended on tablets.