Issue Repo suddenly increased by 8.7GB!

Hello everyone, I had a repo that had grown quite big, 9.7GB to be exact for some time and I was making sure it never passed that mark to keep it below 10GB. Then today, all of a sudden, out of nowhere - with just 2 pushes today of some kb, the repo increased by 8.7GB! How random!

Any ideas why this happened?