I’m not certain what you are looking at. It’s either a folder on your computer, or you are directly accessing the iPad’s folders via an app. Either way, it’s not a safe method for a self proclaimed luddite (or pretty much anyone else). iOS is not designed for direct folder access, and any computer to iPad syncing should be done through iTunes (or one of a couple other third party apps).
Whatever you are looking at, it is a recipe for disaster unless you know exactly what you are tinkering with.
Unlike Windows or OS X on a Mac, iOS is not an open file system. You can’t just copy/move/delete files directly without serious risk of corupting some app or the system.
So, to use iTunes to copy a movie to the iPad, you fist import the movie into iTunes on the computer. Then (with the iPad connected to the computer) you open iTunes and select the iPad icon at the top. This will let you see the various sync options. Here are more detailed instructions.
Sync your iPhone, iPad, or iPod touch with iTunes on your computer using USB
When setting up sync between the iPad and computer via iTunes, be very careful what you do.
As I said earlier, it would be easier to use a third party app like VLC, OPlay, or AVPlay to watch non-iTunes purchased movies. Each of these has several methods of importing movies. None of them involve digging into the iPad’s folder structure and copying files directly too it. Each of these has a method of copying directly between your computer and the iPad via wi-fi. It’s usually called something like wi-fi sharing, wi-fi drive, or wi-fi network.
It works by giving you an IP address to type into your computer’s browser. It can be pretty much any browser; Explorer, Chorme, or Safari. Once you type in the IP address, your compuer browser will go to a page that lets you select and copy files from the computer to the that app. Each app looks a bit different.
(The app must be open on the iPad’s screen for this to work).
Here is how you find and turn on wi-fi sharing in VLC.