I love my tablet but it could never replace a desktop or laptop for me.
I enjoy my tablet because it is quick, easy to use and very portable - ideal for browsing the internet, checking mail, reading a book, playing a game, checking my bank accounts. I also use it as a satnav in the car.
Typing on it for any period is a pain in the neck. Literally. You either have to hunch over it to type with two hands or hold with one hand and type with the other. And of course the keyboard uses at least a third of the screen. You can buy natty little keyboards for them but then it stops being a handy, portable gadget and starts to become a faff. And using the keyboard would drain the battery very quickly.
On the whole, websurfing is great but there is still the occasional site that isn't optimised for smaller screens.
Then there is capacity. The storage is never going to be huge, nothing like even the cheapest laptop. You can store store music, videos and documents to the cloud but that means you have to be online to access them.
I am lucky in that my wireless printer does connect with my tablet so I can print from it. I know other people simply can't do that with their tablet/printer combo. Not a problem if you also have a laptop as you can send whatever it is from the tablet to that for printing.
It seems you don't need a high spec, top of the range laptop - a basic cheapie will do you very well then you may be able to buy a tablet as well.