Compared to other APs (eg. Blood Lords, Age of Ashes, Abomination Vaults) PDF of first book of Season of Ghosts is really big in size (165 GB compared to 25 MB of other books).
Since I often access my books online, this makes loading pdf excesively longer on tablet (not a big issue, but it's annoying).
Is there a reason why the book is so big? Is it a matter of compression? Any chance for "smaller" package (with fixed typos)?
Paizo has a bit of a history of PDF file sizes being somewhat unpredictable (at least to the end user). For instance, the Treasure Vault PDF is 148 MB, while Player Core is 40 MB despite being over 200 pages longer. I've never seen Paizo release an updated PDF purely to adjust the file size, though it would certainly be nice for some of the wildly large files.
If you're frequently accessing the PDF on the same tablet, my best suggestion would be to download the PDF on said tablet so it can be accessed without needing to download the data separately each time. I keep all my PDFs saved on my phone to read while out and about and they all open quickly for me regardless of the file size.
Yeah sadly this has been a recurring issue in APs since Gatewalkers. Season of Ghosts I actually consider to be an improvement over APs like Sky King's Tomb and Gatewalkers which have multiple volumes in the 150-200 MB range.