To insert an existing grid in your report:
Open a report and select Insert, and then Saved Object.
In Type, select Grid.
Select the directory where you want to search for the grid object, then select the desired grid object.
To use the grid object as a linked object, select Link to Source Object.
To use the grid object as an unlinked object, clear Link to Source Object.
see Using Linked and Local Objects.
Click Insert.