A query to isolate top ~3% of desktop pages by page weight:
SELECT
rank, url,
INTEGER(bytesTotal/1024) as TOTAL,
INTEGER(bytesHtml/1024) as HTML,
INTEGER(bytesJS/1024) as JS,
INTEGER(bytesCSS/1024) as CSS,
INTEGER(bytesImg/1024) as IMG,
INTEGER(bytesFont/1024) as FONT,
INTEGER(bytesFlash/1024) as FLASH,
INTEGER(bytesJson/1024) as JSON,
INTEGER(bytesVideo/1024) as VIDEO,
INTEGER(bytesAudio/1024) as AUDIO,
INTEGER(bytesOther/1024) as OTHER
FROM [runs.2015_12_01_pages]
WHERE bytesTotal > (
SELECT NTH(97, QUANTILES(bytesTotal, 101)) as cutoff FROM [runs.2015_12_01_pages]
)
ORDER BY bytesTotal DESC
On quick inspection, most of the outliers are due to lots (or heavy) images, or large autoplay video files:
Running a similar query against mobile data yeilds:
Almost all of the mobile outliers are explained by lots (or heavy) images.