Use the Reorder Pages dialog to change the order of graphs, tables, and group inputs (array inputs define their own page order). The reorder pages dialog can be opened by clicking on the button in the Graph Series Property Panel, the Table Properties, or the Group Input (Interface)
The dialaog lists the pages in the container you are working on. Drag the names of the pages to reorder them. Once you are happy with the new order click on OK to confirm that. Clicking on Cancel will close the dialog leaving the pages in the original order.