What’s brought to the table

The note said:
Come to Ferny Forest
under boughs of night.
Follow Coyote’s howl,
for he will lead you true.
Come to our long table.
Your place is set,
and blood will let.
Nick a vein,
mind the pain.
Words of spell we’ll speak.
Obscenities we’ll leak.
And all, by morn, Medusa’s stone.