So this is a thing:
Apparently there are really people who believe this stuff (link).
Of course there is a perfectly rational explanation - Greek funeral statuary shows the dead enjoying physical possessions - like, you know, picking out the right necklace to wear.
And then there are people who are convinced that time travel has happened and this is a computer laptop. Carved into marble. Without a power source. Because, well, there is a world wide conspiracy to prevent us from knowing about time travel in Greek Funeral Statuary. Or something.