Are you sure they didn't make individual RAR files then combine those into one larger RAR by mistake? Your file could have been made by someone who doesn't understand file compression.
The original rar file seemed to extract 5 other rar files, part 1 - 5.
When i extracted part1.rar it extracted all of the other parts into one large file.
Thank you for your help.
Merete
That's how we used to archive volumes and send large 2gig games split into 25 or more smaller parts. Or large video
That's why it's a good idea to open first to check the contents put it in a folder then and rightclick the first one extract here and they will all unzip one at a time automatically and in then end you have you video/file at the bottom
Like this http://technicalforum.org/sites/default/files/WinRar-SplitToVolumes-Done.png
Here's how it works, splitting large volumes you need to do a bit maths to determin the rar file siaze as this determins how many RAR splits will result.
Split a File / Create a RAR Archive http://features.en.softonic.com/how-to-split-up-a-large-file-with-winrar