You can vary the results by changing both the PDF import engine and the scaling value. But the amount of white space will depend on the amount of text on each line and it's quite likely that you won't ever get perfect results.
Another trick is to print the PDF as another PDF or as an XPS file and then try opening that - that may deal with some odd PDFs.
The easiest way to deal with it is by using the floating trap. If you have multi-column data in your PDF it can be a bit more tricky but there is a solution described elsewhere in this forum.
If you can share the data, I'd be happy to have a look.