To uninstall talk just follow these instructions.
/debian/wheezy/main///install/index.html Chat with another user Debian 7.0 net 0.17-15
sudo apt-get remove talk
Which will remove just the talk package itself.
sudo apt-get remove --auto-remove talk
This will remove the talk package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for talk then this will work.
sudo apt-get purge talk
Or similarly, like this talk
sudo apt-get purge --auto-remove talk
|Maintainer||Alberto Gonzalez Iniesta
|Description||Chat with another user|