The Contracts Window is specifically designed to allow you to view all (contract) students with their current and past contract requirements, and history of signed contracts.
At the base level, each student at that venue that has ever had a contract requirement is listed (even inactive students). If a student does not appear here then one of two things is probably true, either the student has never had any contract requirements, or they are not from that venue. To make a student appear here, you need to either assign a contract requirement to them, and/or change their venue.
The only toolbar button on this window is:
Collapse all sub-tables (ie: hide all contract details for all students).
For each student in this window, there will be a table containing ALL Contract Requirements and Signed Contracts.
TIP: You can change sorting orders on this window, see Sorting Students for more information.