First, I offered the Wikipedia link only because it was easily reachable and as example (I didn't have at hand my informations about Sicilian or Corsican names) to show that the differences between Sicilian and [Toscan] Italian names exist and are noticeable.
Second, proper name are nouns that are exclusive to one reality. That is, place names, personal names (first names, family names, nicknames), mythological names, engine names (plane names, boat names, etc.)... All the linguistic elements studied by Onomastics are proper names. That is why a list of "proper names" can offer non-person's names.
Third, the "dialects" not always are really what a linguist would consider a dialect and not a differenciate language (in the dialectal/linguistic distribution a lot of political questions are in game). This was true in the past with some Romance languages in relation to French and/or Spanish (Occitan, Catalan, Franco-Provençal, Aragonese, Asturian) and it still is true in relation to Italian. Some linguistic realities presented as dialects in Italy (and, but this is another thing, condemned to home life/minor uses, underestimate, ridiculed, etc.) are in fact languages by itselfs. In the case of Sicilian and Corsican, for example, the linguistic reality seems enough clear to consider them Romance differenciate languages.
And, even if Sicilian was not a differenciate language and just a dialect of the [Toscan] Italian, some (if not all) of the names used in this dialect would be exclusive to Sicilia and its influence area.
ETA: a good introduction to Romance languages and its dialects is Les langues romanes
, by Charles
Camproux (PUF, Paris
, 1984, Col
. Que sais-je?)