If you select more than one object, the resulting grid of objects use the appearance attributes of the topmost object.
To set the size of each row and column, enter values for Height and Width.
To set the amount of space that separates rows from one another and columns from one another, enter values for Gutter.
To change the dimensions of the entire grid of objects, enter values for Total.
To add guides along the row and column edges, select Add Guides.