The Manage Modules is an area which can you give you full oversight of all your modules in your instance. It is useful because the only other way to access modules is by navigating the pages they are in.
A typical list of modules with various categories assigned to them
It is possible to assign categories to your modules. These categories have no bearing on the functionality of the module and simply serve as a way for you to manage and filter your modules. The "Exclude" option is for omitting a module from the list when you filter your modules by "All".
The "Default" option is for deciding what list of modules load first when you load this page. These options were originally designed when our modules were used as jobs for customers and each piece of activity was a new job with blocs. Blocworx functionality has advanced a great deal since then and there is no longer a need to create a new module every time a new piece of data tracking begins. For this reason these options are not as commonly used.
This is the date when the module was created
This the date of the last record entered in any bloc on that module.