By default, the Multi Clipboard is empty when Eclipse is started and all contents are discarded when the workbench is closed. This behaviour can be changed using the preferences. See 'Preferences for the Multi-Clipboard' for details.
If persistence is enabled, the contents of the clipboard will be saved in a file named 'multiClipboardContents.xml' in the configured directory when the workbench is closed. They will be reloaded when the workbench is opened. Saving and loading happens irrespective of whether the Multi Clipboard view is activated.