cem said:
The bodies in Herculaneum weren't destroyed - the skeletons were found and the evidence is that they died due to extreme heat.
That same extreme heat carbonised quite a lot of stuff at Herculaneum but not in Pompeii.
That is why we have carbonised stuff at Herculaneum but not at Pompeii.
Remember that each town suffered differently at the time of the eruption with relation to what caused the deaths and the destruction.
Just to add a different point of view to this fact, remember that Herculaneum was buried under 18m, compared to Pompeii's 3-4m.
A pyroclastic flow doesn't consist of lava. Hence it literally "burnt the flesh off the bone," and as Cem said, skeletons were still found. There was no fire to burn the tables etc, and it mostly carbonised anyways, by the solidification of the flows.