Both Uses

Knights of the Round Table
in
Don Quixote
(Auto-generated)

Well, then, in the time of this good king that famous order of chivalry of the Knights of the Round Table was instituted, and the amour of Don Lancelot of the Lake with the Queen Guinevere occurred, precisely as is there related, the go-between and confidante therein being the highly honourable dame Quintanona, whence came that ballad so well known and widely spread in our Spain—†
Chpt 1.13-14 *

Knights of the Round Table = mythical knights who served King Arthur and sat as equals at a round table
I am, I say again, he who is to revive the Knights of the Round Table, the Twelve of France and the Nine Worthies;†
Chpt 1.19-20

Definitions:

(1) (Knights of the Round Table)
mythical knights who served King Arthur and sat with him at a round table that symbolized equal honor and rank

In the Arthurian legends, the Knights of the Round Table are idealized heroes known for bravery, loyalty, and chivalry. The table is round so there is no "head" of the table, showing that the knights are meant to be equals in honor as they advise King Arthur and go on quests, such as the search for the Holy Grail.
(2) (meaning too rare to warrant focus)