As you wrote, the history books do not seem to have much to say about Avlet. Let us see what we can deduce about him based on the way he is cited in the Gemara.

In Avodah Zarah 30a, Rashi and the Rishonim infer that he was a non-Jew. In Shabbos 156b, Rashi infers further that he was an astronomer/astrologer. In Shabbos 129a, he expresses familiarity with medicine (as well as in the Yerushalmi 3:3, where he seems to be familiar with what causes increased or decreased libido).

We also see from the Gemara in Avodah Zarah 30a and Shabbos 129a that not only was he friendly with Shmuel, he ate with and talked with Shmuel frequently. He had such respect for Shmuel and the breadth of his knowledge (Shabbos 129), that he even showed respect for the Jewish laws that Shmuel kept, out of respect for Shmuel (Avodah Zarah 30). Shmuel himself seems to respect Avlet, but on the other hand he does not share all of his secrets with him, even with regard to secular subjects (Shabbos 129a).

What was Shmuel's connection to this non-Jew? Perhaps we can deduce Shmuel's connection to Avlet from what we now know about Avlet's personality. We know that Shmuel, besides being a great Torah scholar, was well-versed in many secular subjects. He was particularly knowledgeable in astrology/astronomy (Berachos 58a, Tosfos Ta'anis 7a) and medicine (Shabbos 108a). Perhaps Shmuel became acquainted with Avlet through his secular knowledge. He may have attended Professor Avlet's courses in medicine or astronomy (to complement or to compare them to his own familiarity with these subjects through 'Sod Hash-m l'Yerei'av"). Or, more probably, the Professor might have come to Shmuel, upon hearing about Shmuel's proficiency in these subjects, in order to learn from him what he could.

Whether or not Avlet taught anything to Shmuel, he recognized that Shmuel had plenty to teach him.

Of course this is all conjecture, but it is the best that I could come up with.

Best wishes,

M. KORNFELD