When saving the notebook in pdf, there are empty spaces on the page. How can it be done so that there are no more empty spaces in the pdf file?
Any change you make the result is the same Wolfram file: pdf file:
Have a look at Option Inspector > Cell Options > Page Breaking. You may have to change the settings for those cells that cause those empty spaces.
Option Inspector > Cell Options > Page Breaking
I used these settings but these spaces still remain.
In the notebook menu item Printing Settings you can adjust page margins. As well as page size and orientation.