You can change the amount of space between text and the inside border of a text box, shape, or table cell. This measurement is called the inset margin. The amount of space you specify is applied equally around the text on all sides.
If there’s no insertion point in the object, select the object. (If the insertion point is inside the object, press Command-Return to get out of text editing mode and select the object.)
Click Inspector in the toolbar, click the Text button, and then click Text.
Drag the Inset Margin slider to the right to increase the space between text and the inside border of the object, or type a number in the Inset Margin box and press Return. You can also click the arrows to increase and decrease space.