When you create a module, put your dimensions on Columns or Rows in Pivot.
For example, the Country Margin Report module has Time, Confectionary, and Region on rows, and line items on columns. Pages is empty.
The order of dimensions in Pivot match the order in a module. Time is the outermost dimension on rows, and Region is the innermost dimension.
Note: If your module contains large amounts of data, it's best practice to use page selectors to ensure data is easy to view.