As it is called means what some people my call it. The first sentence, is an example of sarcasm. Perhaps the person has a difficult life for health, financial or environmental reasons. The second sentence means that some people know the object as a Cavendish but others might know by another name. For example: The sea between England and France is called the English Channel by English speakers. The French never call it that because it is as much French as it is English. So, a Frenchman might say, when speaking English, I crossed the English Channel, as it is called. That implies that he is calling it the English Channel but doesn't agree with the validity of the name, i.e., he would call it La Manche.