Create the first graph and indicate that it should be located in the
open (data) spreadsheet (the default option).
Copy the graph by right-clicking on the graph area and selecting copy
from the pop-up menu. Paste it in the upper left corner of a new spreadsheet
by right-clicking on a cell and selecting paste from the pop-up menu.
Create additional graphs as required, locating them in the open (data)
spreadsheet. Copy these additional graphs to the spreadsheet with the
first graph and place them adjacent to the previous graphs.
Select all the graphs on the spreadsheet by holding down the <Ctrl>
key and left-clicking on each graph. Right-click on one of the charts
and select Grouping => Group from the pop-up menu to group the graphs
into a single graphic image.
Resize the single graphic image to occupy the full page, maintaining
the original proportions. (Format => Object => Size => Lock