The modules list page can become quite big when dealing with a fairly large site or even just a dev site meant for testing new and various modules being considered. What this module aims to accomplish is the ability to quickly find the module you are looking for without having to rely on the browsers search feature which more times than not shows you the module name in the 'Required by' or 'Depends on' sections of the various modules or even some other location on the page like a menu item.
When tabs is enabled via the Module Filter's settings page, a new module layout theme is implemented. This tab layout provides a tab for each package as well as a tab that will show every module alphabetically. The filter textfield is available on each tab but currently doesn't support autocomplete.