apt keeps a cache of the files it used to install stuff.
Once the stuff is installed, they really aren't needed. You might like to look in
/var/cache/apt/archives to see what is there.
Also, if kview version 1.01 is updated to version 1.02, then you don't really need to keep the installation files for version 1.01.
But, if you have plenty of disk space, you can safely just ignore apt's suggestions (I do).