The dinner party was filled with charming conversationalists who made the evening delightful.

conversationalists 是名词 conversationalist 的复数形式。conversationalist 由名词 conversation（谈话、交谈）加上后缀 -ist（表示"从事某种活动的人"）构成，指"善于交谈的人"或"健谈者"。