Measure your table's height and width.
Look for a table of height and width nearly identical to your outdoor table. You may already own such a table. If not, scour department, home-improvement and big-box stores.
Position the found table right next to your garden table.
Throw a tablecloth across both tables to hide the separation between the two. Ensure an overhang of at least 4 to 6 inches on both table sides.
Warn potential users of the table about the gap. If you are throwing a catered garden party, for example, the catering staff as well as the guests should know the table has been extended in a makeshift way. Putting plates, glasses or any weight against the gap can lead to injury or spills.