A more thorough explanation:

A unanimous-consent calendar is a list of business awaiting a deliberative assembly's vote that is not expected to be substantially opposed and is therefore scheduled for a vote without debate, or for automatic adoption unless a member objects. This is also known as a consent agenda or unanimous-consent agenda.

For example, an assembly may have a large number of routine or noncontroversial matters on its agenda. It may find it convenient and efficient to consider these matters under unanimous consent procedure. This gives every member an opportunity to object, but if no one objects, the presiding officer can dispose of a great deal of the agenda quickly and efficiently.

Another example is a legislative committee that reports out a list of bills for consideration by the entire legislature. This list is known as a calendar, and if the bills are not expected to be controversial, they may be placed on the unanimous-consent calendar for a quick and efficient vote.