How to hold Rows in DatagridView

Question

How to hold Rows in DatagridView as we order through table for the Resturent software.

like if i have given orders on a table 7 and later i want to come again and give order on table 7

but i want to keep the rows of previous orders even i close the move in between the different tables.

my Transaction flow is

 

Dine In>Table>Entering food Orders 

 

Please help