Install for Security Upgrades
The macOS 10.13.1 update includes a massive list of security fixes in addition to fixing some common macOS High Sierra problems.
These include fixes to protect your information while using WiFi. You may have heard of a massive exploit earlier this month. This update fixes it so you can use WiFi without worrying as much. You also get a ton of protections from malicious code that could steal your data, even with Apple's new APFS filesystem.
In short, if you are online in any capacity the macOS High Sierra security features are worth upgrading for.