Bundles of tobacco were hung from the many long poles. Openings all around the bottom of the building let in air, which was heated by a wood fire, or later by buring LP gas. Spaces below the tin roof let out the damp air and smoke. I don't know what role, if any, the round steel tables played in the tobacco drying process.
Nowadays very little tobacco is grown in this part of North Carolina, but there are a number of thriving vineyards in the Yadkin River valley.