You will get divided opinions on what to get as most people fall in to three categories, those who use android, those who use Microsoft and those who use Apple.
For me, I am an android girl, so I would thoroughly recommend a Samsung Tablet. It is basically the same as my mobile phone just bigger and does not make calls. If you have an android phone and are familiar and comfortable with how it works then I would stick with that. The picture quality and sound on the Samsung tablet is second to none, and they vary in price from around £150 to £400 ish.
If however you have an iPhone and you are familiar with the system then an iPad is the way to go, my daughter loves her ipad, it is fast, reliable and the retina display is very clear and easy to read. ipads too come in varying sizes and prices ranging from and ipad mini at just over £200 to an air pro at £600 ish.
If however you wish to have a tablet that works on the same system as most computers, then the Microsoft Surface is a good one, this is a tablet that uses windows 10 so it is like using your PC just on a touch screen. These cost anything from £400 up.
These are just my thoughts but I hope they help