You can use the Cut, Copy, Paste, Reorder, Rename and Delete options from the options menu in the Models Pane in the same way as for folders and workboards in the Workboards Pane.
Models are organized in a tree structure (like files and folders). Using the New Folder option, you can create subfolders under Public and Private models.
You can also save a model under a new name using the Save As 
option on the Application Bar.