Tablets don't cut it for real work - good luck trying to type a text blindly on an on-screen keyboard!

Get a Laptop - a real one, that doesn't restrict your choice on which OS to install or on which components to replace!
I'm thinking of a used Thinkpad X201T (convertible) for example. And I can name half a dozen similar devices if you ditch the tablet idea.

btw:
When I was your age we used pen and paper. But then again my grandpa told me the same thing about clay tablets and hand axes.