Numbers for Mac export to PDF adding extra pages

Are those blank tables on other sheets? I believe page numbering starts over for each sheet. Delete those two extra sheets if this is the cause.

Exporting to PDF exports all sheets. Or, if printing to PDF and you choose "all sheets", all sheets will print even though only one sheet is shown at a time in the Print Preview (because each sheet has its own settings).

One thing you could do is remove the extra columns/rows so it fits on a page better. That might be the first thing to do.

When you export to PDF you are given the choice of "fit each sheet to a single page" or "use print settings". If you want the PDF sheets to be whatever size they need to be to fit a whole sheet (at 100% scale I believe), choose the first one. This will put entire tables (the entire sheet actually) on one big page. It is great for viewing because there are no page breaks on a sheet but not so much for if someone needs to actually print it later.

The second one, "use print settings" is not quite what it says. It will export to PDF and make pages that look like what you would get from Print to PDF but the pages are not 8 1/2 x 11, at least according to Preview's inspector. If you want to go this route, you first go to the print settings and set things to print the way you want (each sheet has its own settings). After that you can export to PDF using print settings. Another thing about exporting using print settings, though, is if something has moved or grown in your tables/sheets you will need to check/change the print settings before exporting. It seems to me if you are going to be there checking/changing print settings you might as well Print to PDF while you are there and forget "exporting".