Linear B tablets were records. They were neither literary nor epistolary. They recorded goods entering a palace, the amount, and origin, and goods distributed. Essentially, accounts receivable and accounts payable.

The tablets were also clay, not intended to be permanent. We only have what we have because the palaces were destroyed and the tablets got fired, like pottery, in the destruction.

They provide a fascinating insight in the function of the palace as an economic redistribution authority. The tablets tell the story of one year’s economy, in surprising detail. (One year because they were not intended to be permanent records.)

There are occasional references to names that occur in Homer, e.g. Achilles. There are also references to deities, such as potnia therōn, the mistress of the beasts (a proto-Artemis, if you will).

These names were cited as votive figures, e.g. nine amphorae of wine to the potnia therōn. That kind of thing. One of the more famous examples of a tablet with deities mentioned is from Pylos, Tn 316, written by Hand 1 and possibly written as the palace was burning down around him (Hand 1 is the chief scribe at Pylos—we don’t know the names of the scribes because they didn’t sign their work, but we can tell their handwriting apart).

Backing up a bit, Greek-speaking peoples from the mainland came across Linear A in their trade with and conquest of Minoan palaces. They applied the writing system to Greek, giving us Linear B. The Minoan toponyms in Linear B are there because the Mycenaean Greeks assumed control of the Minoan palaces at Knossos, Mallia, Phaistos, etc. in the late Bronze Age, the Late Minoan III period, specifically. (The story of Theseus provides an interesting mythographc account of the Greek conquest of Crete. Don’t take it literally, but look at the relationship between things that are obviously symbolic. And factor out the love story :) )

Toponyms occur in Linear B, as either the location of the palace where the tablet is made or as the source/destination of goods. There are no literary or ethnographic accounts of other places or peoples.

Linear A remains undeciphered but studied. It may not ever be deciphered simply because not enough of it exists (a substantial corpus is needed for that kind of work—read how Ventris and Chadwick approached deciphering Linear B).

Linear A almost certainly records the language of the Minoans which is also almost certainly non-Indo-European. We see linguistic vestiges of Minoan in some toponyms in Crete.

Linear A derived from the culture of trade accounting the Minoans observed from their trading partners in Cyprus, who in turn were trading with the Levant, particularly the Orontes valley. Cretan Hieroglyphs, Cypro-Minoan, and Linear A show a progressive evolution of that writing. None are likely to ever be deciphered.

And then there is the Phaistos Disc...