I personally rarely need to import tables from .pdf, and if I needed, I used a so-called OCR software (IRIS 14 in my case) → Writer → Calc. For different reasons I considered import from .pdf in another context. You may try what I produced. (See link at bottom.)
Concerning the presently available filters for Import/Export with LibreOffice see the attached spreadsheet document. It contains a few lines of Basic code (basically taken from Andrew Pitonyak’s “Useful Macro Informatiom” for the output of a complete list of I/E-filters. It also contains a Standard-filtered list of I/E-filters whose names contain “pdf”.
The first link below in turn contains a link to an extension offered by Oracle (when the now AOO still was OOo under the rule of that company). That link points to an outdated version. My second linke below points to the most recent version of that extension I know of.
See also:
https://forum.openoffice.org/en/forum/viewtopic.php?t=50304
PDF Import for Apache OpenOffice | Apache OpenOffice Extensions (I never tried it.)
Pdf to Draw to Writer (Adapt it to your needs.)