When organizing GridLines, pressing the More button allows you to import GridLines that had previously been exported. Two different types of import are available.
Import from a .vexp file
Selecting the Import option allows you import a previously exported .vexp file. The imported grids will appear on the GridLines menu.
Import from .vgrid
This allows you to add a Grid to the GridLines menu that has previously been exported to a .vgrid file.
.vgrid files can only be exported/imported one at a time. Export to a .vexp file if you would like to export/import multiple grids.