When you log in and get into you Home Dashboard, you may see some tasks grouped under objects and actions.
This is done to avoid sending an email to every user. It simplifies the life of users by having one single place to look at and see their assigned 'to do'; this is to avoid the infamous "email storm" during projects.
The to-do list is automatically established by XStudio based on the fields in the various objects. For example, for a test, in the "Assigned to" tab, it can be assigned to an "Author" and to a "Developer". Those will see the test as "You must author..." (for the the author) and "You must develop ..." (for the developer).
The to-dos may remain in the home dashboard for some time, even after you completed them. You can set the time it remains by setting the "User Preferences" parameter "Max age (in days) ...".
Note that if you set this parameter to '0', only active to-dos will remain in the dashboard; up to version 3.0 this is set to 180 by default.
for more information about the home dashboard please review: http://www.xqual.com/documentation/user_guide/dashboard_tree.html