Use header rows and columns when you want to label rows and columns. Header rows and columns are formatted so that they stand out from the other (body) rows and columns in a table. Header rows consist of the topmost cells in each column. Header columns consist of the leftmost cells in each row.
You can use as many as five header rows and five header columns. Multiple headers are useful when you want to assign names to two or more header columns or header rows. To format a header to span rows or columns, merge the header cells as described in Merging Table Cells.
If a table contains both header rows and header columns, the top left cell or cells are considered to be part of the header row. Header columns appear below any header rows.
To add header rows or columns, first select a table.
Select the number of headers you want from the header rows and columns pop-up menus in the format bar.
Choose Format > Table > Header Rows or Header Columns > n (the number of header rows or header columns) from the submenu.
Click Inspector in the toolbar, click the Table inspector button, and then click Table. Choose the number of header rows or header columns from the Headers & Footer pop-up menu.
Delete header rows and columns as you would delete any rows or columns. For details, see Deleting Table Rows and Columns.
Header cells play an important role in making formulas in table cells easier to read and create. For detailed information about how to use the hundreds of iWork functions, choose Help > Formulas and Functions Help, or go to Formulas and Functions Help on the web.