A Greek and Nabataean inscription dates the top portion AD 40-71 during the reign of Malichos II.
It has four pyramidal obelisks, a feature typical of Nabataean tombs (Egyption derivation possibly).
From Arts & History book on Jordan.

The lower part (Triclinium) is dated to a few decades later.  The 2-story building appears,
from a distance, with its pediment for each one, to be two different buildings - Roman influence?

Lonely Planet, however, puts the lower section, most likely used as a dining hall, they say,
as the earlier one but they give no references.