Use WiFi File Explorer Pro instead!
OMG Kees_B's method could not be any more complicated! Use an Android app called WiFi File Explorer Pro instead (they also have a free version, but it only allows downloads from tablet to PC, not uploads, which is what you want). When you run it, it gives you an IP address which you can type directly into your browser's address bar. You then navigate to the directory on your tablet where you want to store the movies, then under the "Upload Files To This Directory" section on the right, click on "Select Files" and select the files on your computer that you wish to upload. Check the "Overwrite" box if desired, then click on "Upload Files". Done! The Pro version costs $1.49, but it's well worth it IMHO. I've been using this app for a while now & I love it. Hope it works for you too!