You're using it wrong. You need a laptop. A laptop tethered to a smartphone or with an internal cellnet card.Why is this important ? Because when I am in the field I don't have Internet access on my laptop. I don't need Numbers destroying the formatting on Excel files that I have to email daily.
Of course a 'big boy' office suit (MS are listening ?) would be nice. Not the dumbed down mobile crap, but a real desk top equivalent.
Sounds like you're trying to use a tablet for more than designed for, probably like many, simply because its the new hip thing.