To delete your WiFi history - you have to check the model of your WiFi router.
Some routers allow the owner to see browsing history. In most cases you will need the IP address of your router. The address is easy to find because it is usually printed on the side of your WiFi router. In your browser enter the IP in the address bar and it will show you the login page. Enter the admin username and password for your wi-fi router. If you don’t know the admin's username and password you may need to reset it. After you logged it - go to advanced settings and then to Administration. Then click on Event Log to see browsing history. There you can see all requests that users of your WiFi router made. The log is called WiFi router history. To clear the log - click “Clear WiFi history”. This should delete the WiFi history of your router.