The ex-Brentford winger Tabb, 24, has signed a two-and-a-half year deal with the Royals which may extinguish Reading's move for Reds winger Jamal Campbell-Ryce.
JCR was apparently subject to a seven figure bid from Steve Coppell's side on Friday but now they have signed winger Tabb it may mean the Jamaican could be staying at Oakwell.