Looking for good cheap tablet

Just don't buy those chinese tablets. They are very poorly made.

As owner of an Acer tablet, I can recommend buying one of them. Unfortunately, I am no expert. The "old" Iconia series seem to start off 90€...

Reading e-Books is much better on 4:3 screens, in my opinion.

go medieval. get a wax tablet. tabula rasa is best tabula

iPad 2s should become alot cheaper with the new gen out, so keep a look out for left over stocks

I have the Asus Memo HD 7. It's been okay. Doesn't play all the android games, but so far plays everything purchased on Humble Bundle for Android. It won't play several games from the Google play store. My only complaint about this tablet is sort of a big one. When I let it go completely uncharged, I couldn't turn it back on again. I've heard this has been an issue with Asus. If I had been smart I would have returned it to Asus. It had a one year warranty. But instead I had it taken apart and reconnected the charge that way. Now the screen has places where it doesn't sense touch. So as long as you don't let it get completely discharged... :) it's a good tablet. It looks to be about 140.00 US$ on Amazon for the 16GB and you can add a memory card, I think a 16GB memory card can be added. I've seen it for lower. Maybe 120.00 US$ on sale...
My friend has the Nexus 7, which I think is better, but slightly more expensive. You can get the unlocked (older model) for about 160.00 US$ 32 GB. I don't think you can add a memory card.
I'd suggest waiting for Christmas or Black Friday sales if you are getting it delivered from the US. The holidays aren't too far away. If ordering from the US this is a good place to look for sales https://www.dealighted.com/
Not sure what the holiday sales are like in Spain :)
I store a lot of ebooks on tablet, free books from Amazon, using the kindle android ap which I usually find with this search
http://www.amazon.com/gp/search?node=154606011&field-price=0-0&redirect=true (several foreign language books on here as well) and I get books from the humble bundle ebook deals when they happen. Free ebooks here too https://www.bookbub.com/home/ gives you daily updates with free google ebooks, smashwords and Amazon ebooks. I don't think bookbub has books in spanish yet but they are working on it. Smashwords has Spanish fiction, but not sure how many.