Yesterday, all of a sudden after my laptop restarted, I noticed the C drive was showing low space which had 15GB free space earlier. I ran a scan disk, restarted and then finally look at individual file sizes and noticed Index 2009-09 and History file located in Chrome user data folders ( C:\Users\Sankeerth\AppData\Local\Google\Chrome\User Data\Default ) is taking 10GB and 7GB and thumbnails 2 GB. This happened after Chrome crashed and had to close.
What are these files
The History Index files are mainly used to store the text-based content of any webpage you visit. When you search your history for a word you remember from some webpage, it’ll look through all of the index ’till it finds it. Over time, that can really add-up.
The thumbnails file is a file that stores all your websites’ favicons, and page "snapshots". When you visit a site/page, a small thumbnail picture of it is saved. Again, this can also add-up over time. e.g., the top 9 websites on the New Tab pages get their thumbnails from the "Thumbnails" database file. In the old History viewer, you could see thumbnails of every page when you entered a search term. I just manually deleted these files form these locations. Sometimes uninstalling it from Control Panel > Add/Remove programs and reinstalling from the download page help too.