rmvb file info

Howdy everyone. Lets jump right into this. I have a large dvd collection. I am going to the big sandbox in a small amount of time. I cant take my dvd’s with me(too many).What Im trying to do is convert them all to the smallest video file I can, to put as many movies on a disk as I can. I was told that rmvb was the smallest video file out there...sorry to be off the subject but please help or direct me to help... Thnks

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