Is lunch stop considered a stopover?

If you are taking the car and stopping at a specific restaurant, it's considered a separate stopover. 

If you go to a restaurant within walking distance of one of the existing stopovers, then it's NOT considered a separate stopover. For example, if one of your stopovers is Nami Island and you go to a restaurant inside or near Nami Island by walking (without taking the car to go to the restaurant), it's included in Nami Island. 

Reasonable stops at rest area along the highway is NOT considered a separate stopover. You can often have lunch in these rest areas. 

In order to avoid paying extra for a lunch/dinner stopover, please find a restaurant within walking distance of one of your existing stopovers if possible and walk to that restaurant either before or after touring that stopover. Then you won't have to pay for extra for a lunch/dinner stopover fee.