Hungarian origin. My Grandfather and his Parents immigrated to the USA from Hungary in the early 1900's. My Grandfather Steven Raboczkai had this surname. He was from Hungary near the Yugoslavian border. He said the name was originally Spelled Raboczkay. When the borders changed location they made the family change the last part of the name to "Kai" in place of "Kay". He said it was because his Village was Annexed into Yugoslavia. He later changed the name back to his original in the 1940's. Other family Relatives with this name stayed behind and didn't immigrate to the USA. His Father also returned to Hungary by himself in the 1920's and never returned. He may have started a new Family when he returned to Hungary,