Names, especially last names, are a huge symbolism in the Assassin's Creed Series. Here's some examples that I've noticed.
Altair - His name translates to "the bird," or more specifically, the eagle. There are numerous references to eagles throughout Assassin's Creed, from eagles at viewpoints, to the many "eagle achievements."
Ezio Auditore - His last name, Auditore, translates to "auditor", a job that has a lot to do with accounting, which is what his father was. Auditor also means "someone who listens," which Ezio does plenty of, trying to listen for anyone connected to his family's tragedy.
Desmond Miles - His last name, Miles, references the long journey he has ahead of him.
Lucy Stillmann - She is the "still man" of the Assassins, a sleeper agent planted inside of Abstergo.
Shaun Hastings - Most noticeably in Assassin's Creed II, he is very "hasty," always pressing Desmond and the to hurry up and finish their tasks.
Rebecca Crane - Like a crane, she overlooks Desmond in the Animus, making sure he is alright. (Cranes typically stand still, almost like a sentry, for hours.)