While the file is fairly excessive for such a small document, it seems to be the result of extremely high resolution pages. In contrast to the other scenario I ran at PaizoCon online (Beacon Code Dilemma), the map images remain very crisp and clear when scaled for a useful play area.
I would suggest that Paizo separate pdfs into a normal resolution booklet and a high resolution map package in the future rather than oversampling the text or including blurry maps. But given only the two subpar options, I can work around oversized files more easily than generating missing detail on what should be a map.