Defining Object Placeholders
You can create a placeholder on a master slide to hold tables and charts. When you
add one of these items to a slide based on that master, the object automatically goes
into the placeholder at the specified position and size.
To define an object placeholder:
In the Master Slide navigator, select a slide (to open the Master Slide navigator, click
View in the toolbar and choose Show Master Slides).
Open the Master Slide inspector and then click Appearance.
Select Object Placeholder.
Position and size the placeholder.