Here's who I think Squidward was refering to with each name:
Halbert (Incidental 38)
Norma (Incidental 48 or Incidental 49)
Isabelle (Incidental 27 or Incidental 42)
Gus (Incidental 37A)
Chas (Incidental 41 or Incidental 105)
Pelar (Incidental 82 or Incidental 87)
Jess (Incidental 48 or Incidental 49)
Cara (Incidental 48)
Ivy (Incidental 48, Incidental 49, Incidental 106 or Incidental 107)
Marv (Incidental 27 or Incidental 42)
Mable (Incidental 47)
Mavis (Incidental 48)
What do you think?