Hi,
installed modules create menu entries - like in windows apps add its shortcuts to menu start.
Test submenu is created by "Tests" modules. You can uninstall them this way:
- log in as administrator
- menu->administrator->modules administration
- set setup type to "Advanced"
- expand Tests tree
- select for every module inside and for "Tests" module "not installed"
- click "Save" in action bar
Cheers
Paul