There are exactly fifty-seven items in the change log for Chrome 61.0.3163.100. Some of those changes are version increments and other housekeeping; about forty are actual changes to functionality. Most of those changes are fixes for minor issues. Three of the fixes are for security issues.
If you’ve stopped trying to prevent Chrome from updating itself, it will no doubt proceed with this update automatically. But since the new version includes security fixes, it’s a good idea to make sure. Click the main menu button (three vertical dots at the top right of Chrome’s window), then
About Google Chrome.