Configurations created for yEd's properties mapper are global, i.e. your configurations will be available when importing your updated Excel data.
I am not sure I understand what you mean by "formats" but if you are referring to the visual style of your nodes (and their labels), you can add your nodes as templates to a user-defined palette section. To do that, go to "Edit" -> "Manage Palette", then click "New Section", specify a name for the section, and click "Ok". Then right-click one of your nodes in the editor area to open the node's context menu and choose "Add to Palette". The resulting new node template may then be used in new documents, in properties mapper configurations, etc.
Unfortunately, the yEd manual is currently not available as single PDF document.