In addition to the batch idea, which is good, you can also bring in the AVI files one at a time. The batch process automates this.
Also, what if the way you would like to split up your files into events does not correspond with the AVI files?
In this case, you can load all 30 files into MPEG Streamclip. Then, to create your first clip (or first Event), move the playhead to the In point and press the I key. Then move the playhead to the out point and press the O key. Then hit File/Export as QuickTime. Select your output format and give it a name. Then repeat until you have all the clips or Events you want.