Archos 80 - £125
The Archos 80 has an 8" screen, runs Android and sports a 1.6ghz ARM processor so should be fairly speedy for a budget machine. It runs a fairly pure version of Android - compared to the manufacturer-specific bloat you get from the likes of Amazon Kindle and Samsung. The only downside is that it has only 8GB of memory - which is perhaps easily filled, so you’ll have to keep an eye on usage.
Looking for a tablet but not entirely sure that you need one? Aren’t a phone and laptop good enough? Then why not go for a budget tablet rather than splash £400 on an iPad. Here’s a selection of tablets that you can pick up for between £100 and £200.