This is a well known practise in Spain. I com from Spain and I have always seen my family (parents and grandparents) drinking coffee after lunch and, then, doing a nap on the couch. Usually, we sit on the couch, take the coffee together and then every person takes a newspaper or magazine and after a few minutes of pseudo-reading everybody is sleeping or in a state of deep relaxation. We sleep for 20 minutes. That's all. I guess this is very common in Spain.
This works well because we often take lunch at home. But, now that I have lunch at the office, I do the same. I have a 1 hour pause. The first half hour I have lunch, then I take the coffee and I go to the office to sleep on the floor, on a very thin mattress. If my brain is too active, I listen to a foreign radio station with my iPhone. I like to listen to ICI Radio Canada (in French). When I have lunch here, they broadcast the morning news and commentary. The news are about stuff happening in Quebec. It is interesting enough for me to forget the work stuff, and dull enough to induce me into a deeper relaxation state, which allows me to fall sleep fast. Being the broadcast in a foreing language, also helps to fall sleep. I often dream during this 20-30 minutes naps.
An interesting detail is that I had to learn this habit. I remember being a child and being pissed off because I wasn't allowed to make noise after lunch. Now, that I'm a father, the roles are changing and I'm the one sleeping after lunch.
By the way, at night, in order to fall sleep, I never take phones, tablets or computers to my bedroom. Instead, I take a shortwave radio and I tune the BBC world service news (fortunately, in Spain we can hear the broadcast directed to Africa). I put a 30 minutes timer on the radio and I almost never hear it stopping, because I fall sleep before. The day that the BBC will shut the SW broadcast, I guess I will take a bluetooth headset or speaker to my bedroom, but not the iPhone. It is very important to avoid computers in the bedroom.