Here are some definitions of a (literary) salon, paraphrased from around the web:
“Originating in the 17th century, literary salons were once the perfect training ground for aspiring authors, helping them refine their ideas and improve their writing.”
“A salon is a gathering of people held by an inspiring host. During the gathering they amuse one another and increase their knowledge through conversation. These gatherings usually aimed either to please or to educate.”
“The literary salon, the 18th-century gathering where intellectual giants would debate and inspire or infuriate each other, has been recently reborn for the 21st century, with new salons appearing throughout the country and on the internet. During the Enlightenment, salons established by charismatic individuals allowed the great talents of the age to discuss their writing – creating the work and ideas that changed the course of Britain’s artistic history. Many classic works would never have appeared without the semi-public gatherings. Now there are meetings once again, so members can bounce ideas off each other and read unfinished essays to gauge reaction before redrafting.”