This additional window is activated by the Store/restore button. It's purpose is to allow you to create a database of configurations that you'd like to keep (after all if you've spent some time configuring the look of a plot you don't want to have to type it all in again when someone asks you to tweak the postscript).
The configurations are identified by two elements, a Description entered by you and the date when the configuration was created. To create a copy of the current configuration (note this doesn't include the spectra themselves) just press the Store button. This creates a new entry with the description New configuration. To change the description just double click on this text and type in your changes. Remember to press <Return> when you're done. To remove any un-needed configurations select their rows and press the Delete button.
To restore a configuration just select it and press the Restore button. The actual data is stored in the file: $HOME/.splat/PlotConfigs.xml. If things seem badly broken then try deleting this file.
SPLAT-VO -- A VO-enabled Spectral Analysis Tool