Hello
Can we block all ads when we surfing internet using routerboard?
Yes. But you’ll need container package and create a container like pihole
RouterOS Container page uses Pi-hole as an example: https://help.mikrotik.com/docs/display/ROS/Container
Container support is RouterOS version and device hardware specific. Your device mileage may vary.
Of course you need a ROS7 with ARM based CPU device as core. Very important.
Regards.