sudden reboot

No dump so not much we can do to debug this.

Please make sure your pc is configured for small dump files: How to Configure Windows 10 to Create Dump Files on BSOD

If that doesn't give us a dump on the next failure, try Driver Verifier.

Driver Verifier is a diagnostic tool built into Windows 10, it is designed to verify both native Microsoft drivers and third party drivers. Driver Verifier's verification process involves putting heavy stress on drivers with the intention of making bad, outdated, incompatible or misbehaving drivers fail. The required result is a BSOD (Blue Screen of Death) which will generate a crash dump for debugging purposes.
Machines exposed to Driver Verifier will run very sluggishly due to the stress being applied to the drivers.

Driver Verifier - Enable and Disable in Windows 10

Warning:
It is not advised to run Driver Verifier for more than 48 hours at a time. Disable Driver Verifier after 48 hours or after receiving a BSOD, whichever happens soonest.

Always create a Restore Point prior to enabling Driver Verifier.

My guess is that this is the culprit

Code:

Event[2484]:
  Log Name: System
  Source: Microsoft-Windows-WindowsUpdateClient
  Date: 2016-06-14T22:17:16.396
  Event ID: 19
  Task: Windows Update Agent
  Level: Information
  Opcode: Installation
  Keyword: Installation,Success
  User: S-1-5-18
  User Name: NT AUTHORITY\SYSTEM
  Computer: DESKTOP-PK1L93R
  Description: 
Installation Successful: Windows successfully installed the following update: Cumulative Update for Windows 10 Version 1511 for x64-based Systems (KB3163018)

I don't think you should worry about reboot unless it's locked in a reboot cycle. It could be just a simple error. Persistent BSOD, yes.

A search for bsod and KB3163018 gets lots of hits, so definitely a good possibility.