Hammett was essentially washed up by that point, having written all the novels he would ever finish. Chandler - the older man - had only published short stories so far.
Other still-remembered pulp masters at that meal included Norbert Davis, Dwight Babcock, and Horace McCoy. You can see a photo of the event here.
"Everything goes back to Saint Hammett and Saint Chandler.” - Larry Kleinfeld