It is possible in the event library, but I would suggest that you do it in an app called MPEG Streamclip. It will be much faster and easier to do it using MPEG Streamclip.
Download MPEG Streamclip here.
http://www.squared5.com/svideo/mpeg-streamclip-mac.html
Drag your large file into MPEG Streamclip.
Now, set your playhead to the beginning of the first event, and type i for in point. move the playhead to the end of this clips, and type o for out point. Then, use FILE/EXPORT TO QUICKTIME. Choose Apple Intermediate Codec as your codec. (Note: if your original clips are in DV, you may wish to stick with DV. Otherwise use Apple Intermediate Codec, and don't change any of the settings. Give it a name and location. You can import this into an iMovie Event using FILE/IMPORT MOVIE in iMovie.
Repeat this until you have all the clips you need.