When generating a Notebook in PDF, tables (column spacing, etc.) don't format in the same manner as they do onscreen. The columns appear to all default to even spacing which makes reports harder to consume.
The status of this idea was out of date. Since this idea was submitted we have implement improvements that will preserve the formatting of reports in PDFs:
PDFs can now be optimized for printing or for viewing online, including printing to various page sizes.
Columns in lists and pivot tables can now be resized. These formatting changes will also be preserved when exporting to PDF.