Crowding around the display tables like pigs at a trough, Harvard bibliophiles mobbed the fifth annual Bryn Mawr Book Sale in its opening skirmishes yesterday. In the two hours of the sale a mixed multitude of students, book dealers, kindly old ladies, and Harvard faculty members battled for positions and bought 3600 volumes of "Fiction, Literature and Ten-Cent Miscellany."

Among the first bargains to be snapped up were a 29-volume set of Dickens ($6) a 10-volume Poe ($1.25) and a 17-volume complete Hawthorne ($3). An unidentified 'Cliffie out-maneuvered two Cambridge matrons for a rare $4 set of Casanova's Memoires.

Inexplicably, 48 volumes of Sir Walter Scott ($6) remained unsold, and a table full of books and periodicals devoted to the proposition that Francis Bacon wrote the plays of William Shakespeare was left virtually untouched.

These neglected masterpieces, along with a fresh stock of non-fiction books, will be available when the doors of the Parish House, First Unitarian Church, reopen at 10 a.m. today. Tomorrow, sheet music dating from the Civil War will be added to the stock. On Thursday, the sale closes with a half-price day.

Books are donated by Bryn Mawr alumnae and priced by Mrs. Lyman H. Butterfield, with the aid of her husband, the editor of the Adams Papers. Proceeds of the sale are used to send bookish girls to Bryn Mawr, and the cycle begins again.