I don’t know if this is the easiest way, but it has worked well for me. I have a folder on my computer set up to be accessible from the local network. When I need to put some files on the deck, I switch it into desktop mode where I have a shortcut to the network folder. Then I just take the files out and put them wherever I need them on the deck.

I have been using mine to read comics recently, since the screen is larger than my phone’s and the aspect ratio is about right when turned on it’s side.