DG834PN how to use as wireless extender

Thank you, but I am a private house. All I want is for my friends and family to be able to use their laptops, iPads, iPhones and Androids when they are visiting me, just as I use mine in their homes. It's just that my home is a very large bungalow so a single wireless router cannot reach all around it.

There has to be an easier way than buying a solution aimed at a hotel? Mine cannot be an unusual problem?

Thanks for your help :)