One way. You can use a USB flash drive & the camera connection kit.
Plug the USB flash drive (works the same with an SD card) into your computer & create a new folder titled DCIM. Then put your movie/photo files into the folder. The files must have a filename with exactly 8 characters long (no spaces) plus the file extension (i.e., my-movie.mov; DSCN0164.jpg).
Now plug the flash drive into the iPad using the camera connection kit. Open the Photos app, the movie/photo files should appear & you can import. (You can not export using the camera connection kit.)
Using The iPad Camera Connection Kit
Secrets of the iPad Camera Connection Kit
Trying opening up iTunes, then via the top menu bar, select "file / add to library". You should be able to navigate to this movie file, and import it.
Once in iTunes, you need to go to the "movies" section of iTunes, select the movie, then via the top menu bar, select "file / creat new version / create iPad or Apple TV version"
Once you have the video in a version that is supported by the iPad, you can sync it normally.