Are /var/cache/apt/archive files essential?

["Thomas H. George" <xyz@spininternet.com>]

Suddenly I have used up all 9 Gbytes of the /var partition.  I 
eliminated some of the gzipped log files but that didn't help much.  For 
the moment I moved all of the /var/cache/apt/archive files - about 3 
Gbytes - to another partition. The system is still working but I don't 
know how much damage this might cause in the future.

I note that there are multiple entries for most of the packages in the 
archive with dates going back two or three years.  Perhaps it would have 
been better to weed out the older entries.  If so, is there a simple way 
to do this?

Tom George