Trivedi means "one who knows
three vedas'. They are Gujarati Brahmins and you could say that they belong to the "knowing" ataks (surnames) like Vaidya (another "knowing" ataka).
In other
words, these Gujarati "knowing" surnames (atakas) are naturally the highest of the Gujarati Brahmins.
It is also known that the Gujarati
girls of these "knowing" Brahmin ataks are open to matrimonial alliances with other Gujarati upper castes, especially afluent upper caste like Lewa Patels.