If you have opened several projects in the Work pane, you will see many tabs—one for each object that you have opened. This can make it difficult to find the projects that you are actively working on. When this happens, you can close old projects that you no longer need in the Work pane.
Procedure
In the Work pane, click the X in the project tab that you want to close. Closing a project removes the tab in the Work pane.
If you close a project, you can open it again by using Show or by clicking
in the Work pane toolbar, typing the project name, and clicking OK.
If you do not remember the name, you can query first, then follow the instructions in Showing properties in the Work pane.