"""  
This  record  is  part  of  the  Page  Settings  Block. It contains all
horizontal manual page breaks.
Record HORIZONTALPAGEBREAKS, BIFF8:
Offset  Size  Contents
0       2     Number of following row index structures (nm)
2       6nm   List of nm row index structures. Each row index
              structure contains:
                Offset  Size    Contents
                0       2       Index to first row below the page break
                2       2       Index to first column of this page break
                4       2       Index to last column of this page break
The row indexes in the lists must be ordered ascending.
If in BIFF8 a row contains several page breaks, they must be ordered
ascending by start column index.
"""
xlwt - How to add page breaks to an Excel File?