Hi Richard!
It's only obvious once you know how to do it.
My method is to long press (or tap and hold) on the file I want to transfer. A menu will pop up. I then tap Copy, which puts a little up-arrow tab thingy at the bottom of the screen. Next I tap over to the Local tab at the top, find the download folder (or whatever folder you want to move the file to), pull up the tab at the bottom of the page, and tap on the icon of the file I am moving. If it works, a confirmation message will pop up.
I'm pretty sure you can do the copy and paste using the menu button as well, and you can copy several files before you start pasting.
Good luck!
