The scrapbook allows Java expressions, to be run, inspected, and displayed under the control of the debugger. Breakpoints and exceptions behave as they do in a regular debug session.
Code is edited on a scrapbook page. A VM is launched for each scrapbook page in which expressions are being evaluated. The first time an expression is evaluated in a scrapbook page after it is opened, a VM is launched. The VM for a page will remain active until the page is closed, terminated explicitly (in the debugger or via the Stop the Evaluation button in the editor toolbar), or when a System.exit() is evaluated.
There are several ways to open the New Java Scrapbook Page wizard.
Running and debugging
Java scrapbook page