Sentence:  As the principal table was always placed upon a "dais", it began very soon, by a natural abuse of words, to be called itself a <WSD>Dais</WSD>, and people were said to sit "at" the <WSD>"dais</WSD>", instead of at the table "upon" the "dais". 
Meaning of the word marked with <WSD> tags:  An elevated table in a hall at which important people were seated; a high table. (13th–17th c.)