What are you referring to? The surname statistics don't even include Spain, let alone Catalonia. If you are referring to the Usage list, that refers to cultures as defined by language, not geographical areas or countries. That is it indicates a name is reported to have been used among Catalan speakers. Cultures frequently adopt names from other languages, but in the process it may be altered to suit their own phonology. As Catalan is distinct from Castillian Spanish it may be useful to someone who knows only that their family is from Spain but can find no such Spanish name, to learn that it is actually Catalan, or Basque or Galician (or Portuguese or Occitan, as languages don't always obey borders).