Although I see your point (11.6" vs laptop), many older laptops started with 12" and 14" screens, but they were 4x3 rather than widescreen which is why so many laptops now are 15.6" / 17" (while some Apple use 13").
If using anything where typing is involved, I'd resist a tablet, unless you can get, say, a bluetooth keyboard (perhaps an extra 20 quid) for the tablet. Really, for typing passwords, entering bank info, I would not want to risk typos or the wrong account number (eg transferring cash to someone else, don't want it to end up in wrong account, belonging to a stranger - morally they should return it but banks have to also protect their privacy, so better to avoid the chance of a mistake, in my view).
Personal preference, laptop over a tablet any time. More robust, can play video off a DVD, easy (if you choose carefully) to have HDMI into a big TV, so could play video on flat screen, if you want. Just more flexible and more software around than for many tablets, and tried and tested (however good the iPad or Android tablets, I'd stick with a laptop with wireless keyboard and mouse).