How can multitasking experience be improved on Android tablets?
Android 7.x Nougat officially introduces multi-window. With this feature you can now run 2 apps side-by-side and drag the black interpolation bar to adjust the window size (3 tiers available).



With the aid of Taskbar things get even better - with proper settings you get Windows-like task bar and resizable, movable multi-windows.



Ultimately though, without the ability to natively open multiple instances of one app, document abilities will be crippled to an extent. Wired video output is also absent, making presentation difficult, though if you have Miracast-compatible devices this isn't much of a problem.

Get started loading your Nexus 10 with Nougat-based custom ROMs by visiting XDA-Developers.

Do note that, due to the age of the tablet, Nougat won't run very snappily and you can't expect to multitask heavily.