Page Setup Dialog - Print Area
You can select rows or columns to be printed on every page of the output. This is commonly used for printing column or row names. To enable this, enter the range of cells to be repeated in Rows to repeat... or Columns to repeat... field. Instead of entering them manually, you can also select columns or rows to be repeated using the mouse.
WARNING
Note that the rows and columns must be entered as ranges. That is, if you want to have first row repeated, you must enter 1:1, not just 1. Similarly, to have column A repeated, you must enter A:A.