Play store My App section
You might want to see apps you have installed previously but since uninstalled in order to find an app that you but want to recommend to a friend. You might uninstall an app by accident and want to find it again easily.

Google Play needs to keep track of this information anyway, for two reasons:-


You can only review an app you've installed;
Even after uninstalling a paid app, it remains available to you, and you can reinstall it again without paying.


Deleting an entry only hides it from the list (on all your devices and the web interface), and has no other effect.