Firstly, you should always be using the render queue when you output out of After Effects. Never use File->Export (unless there is a really specific thing that the render queue doesn’t do).
Also, you want these as data files right? or do you intend the viewer to watch them on their DVD player on the TV?
Are you rendering .AVI uncompressed? this would explain the large file size. you need to choose a codec. If it is mostly for windows users maybe try wmv9 or for quicktime maybe an MPEG4 or h.264 … getting the correct balance between file size and picture quality is something you will need to experiment with.. and maybe ask more specific questions in the “Compression Techniques” forum..
If you are trying to re-author a DVD to play on the TV that is a different procedure.
If this doesn’t help or doesn’t make sense maybe tell us in more detail what you want to achieve.