if you go into the desktop you can have two programs snapped to half screen side by side. i.e. word next to one note. then you can also have one of the modern full screen apps snapped to the side effectively giving you three apps side by side. i wouldnt use it this way myself except maybe to have a play list running on the left or right but it can be done.
what video format do you want to play that you cant play natively? there are a couple apps now that have pretty much everything covered. one of them is "powerdvd mobile" plays mkv etc.