My dad also asked me the same question, if I would like a tablet or laptop
I bought a laptop in the end, because I think tablets are useless, if you have a smartphone & laptop...........
- Laptop has even bigger screen than tablets, so better for watching movies & doing other stuffs
- Physical keyboard is always better than touch keyboard
- Laptops have many high end games, which are better than those of Android (I'm a gamer)
I agree that laptops are heavier than tablets, but you can still carry it around in a bag.
I would suggest that you get a laptop within 40k, atleats & be happy
I suggest that you try using a tablet or an ipad for Excel work first - it is not the easiest thing. You need to shift between alphabets, numbers and symbols on the onscreen keyboard that it will become frustating... Especially for spreadsheets.
Go for a light netbook... May be 10 or 11" screen... You can choose Linux with LibreOffice instead of MS Office for spreadsheets with Excel compatibility. Should be able to get it under 20k...