I cannot download any video from my camera to my iPad

Need more information. What kind of camera? What file format does the camera produce when doing video? I recall from some old posts and responses that certain cameras do not produce compatible video (the file format was correct, but such attributes as frames per second, etc. were not within iPad specs).

That's simply the container, need more specs.

See the compatibility table via the link

http://www.apple.com/ipad/specs/