"To my dear friend"
And
Any Ancient Greek inscription that would fit!
For a simple and short dedication ...
(< in the place of the dots you write in capital letters the name of the person to whom you present the gift, e.g. ΑΡΙΣΤΟΤΕΛΕΙ) ΤΩΙΦΙΛΤΑΤΩΙ is enough, but if you like something more, like a greeting in the beginning of a letter, you could add
ΠΟΛΛΑΧΑΙΡΕΙΝ, the complete phrase meaning "to (name) e.g. Aristotle, my dearest friend, I wish a great joy".
In Classical Greek, when only majuscule letters were used, this was the standard form of the phrase, whereas later in the Byzantine period, when the minuscule characters had been invented and used, one could see the phrase having the form e.g. "Αριστοτέλει τῷ φιλτάτῳ πολλὰ χαίρειν”.
P.S.: Am I correct to suppose that an “i” has crept into “autodidact(i)us?