Yes you can download a PDF to your iPad.
If you are using Chrome, this article from the Google Support page tells
you how to download a file on you iOS device: https://support.google.com/chrome/answer/95759?co=GENIE.Platform%3DiOS&hl=en
If you are using Safari:
1. Open the PDF in the browser.
2. Click on the Share button at the bottom of the
browser window.
3. Scroll right select ‘Save to Files’
4. Select where you want to save the file, and click
Add on the upper right.
5. The file save to your device and will now be
available in the Files App.
