A few years ago I would have suggested going for a netbook. (I find mine very useful for word processing on trains). However they've fallen out of favour with manufacturers and consumers and are no longer manufactured. (They're available secondhand or 'refurbished' but you might find that the battery life of such an item isn't very good, forcing you to fork out for a new, expensive battery).
So I'd recommend a laptop instead. However there are two things I'd avoid:
1. Chromebooks. They're designed on the assumption that you'll always be online and that you'll largely use cloud-based storage and programs. I hate the idea!
2. Laptops that come with 'free' Office 365. You actually get a year's subscription (that's simply been added onto the cost of the laptop anyway) and you'll then find yourself tied into paying Microsoft annually thereafter. PC World/Curry's seem to have an arrangement with Microsoft to
only sell laptops that come with Office 365 pre-installed, so I wouldn't even consider shopping there. (OpenOffice does everything that Office 365 can and it's free!).
Something like this might be suitable:
http://www.very.co.uk/acer-es1-131-intelreg-celeronreg-processor-2gb-ram-32gb-storage-116-inch-laptop-with-optional-microsoft-office-365-personal-red/1461244939.prd?aff=google&affsrc=acquisition&cm_mmc=google-_-PLA+-+Electricals-_-Electricals+-+Computers+-+Laptops-_-_63938667418&k_clickid=053b7e43-456e-4365-a1f8-e68b00e6ff0a&gclid=CI_s0puro8cCFUXItAodV9ICRQ&kpid=17419453
(Note how much adding Office 365 would cost if you wanted it with that laptop. It adds on £90 extra. Why pay that when OpenOffice is just as good?)