Which ~8 inch tablet with phone functionality (in UK)?

[ogremage]

I have a hiking / backpacking trip planned and I've realized I'd like to take a single device with me - a tablet with a built in mobile phone (ability to make and receive GSM voice calls).

Considerations:

• Weight - below 320g / 11oz would be best, the lower the better
• Price range - something below GBP 400 but if I can buy it used for GBP 200 off eBay it would be best. I'm ready to pay for quality, but care about value for money.
• Off contract
• Screen size - I'd like to go 10'' but it will be too heavy. I think 8.0 in or 8.4 in is most realistic. 7in is likely too small, although maybe if it ticks all the other boxes really well I could consider it. Anything smaller is right out (I have a SGS4 as my phone now).
• Location - UK
• Typical use - reading eBooks, browsing the web, writing a few e-mails or notes. No gaming.
• Water/dust resistance a nice to have but not a show-stopper.

What are my options?

What I looked at:

• My prime choice now is "Samsung Galaxy Tab 3 8.0 with 4G". Do I read it correctly that it has a built in phone?
  
• I wanted the Samsung Galaxy S 8.4 but I'm not sure even the 4G model has built in phone (does it? or only data?).
  
• Samsung Galaxy Note 8.0 - getting on the heavy side and I'm not sure how it is better than Tab 3 8.0 with 4G.

What other devices I'm missing which would be good?