I´m getting crazy

[Finfarin]

I always have problem when I try to burn. When I try Nero it makes a 1Gb movie file to much much more. That file is only a small part of a movie so I cant burn it since Nero would make them all to like 14Gb.
Then I trie to place the movie files (by the way, its vob files) in DVD-lab but it is three options that sais: Demultiplex to elementary streams, Use it directly as it is and the third sais first join vobs then use them without demultiplex. Geez!

[Finfarin]

Just tell me if a 696Mb big movie possibly can become 3Gb when using Nero Vision express 2.