The former Chelsea defender has been training with Harry Redknapp's men for the past six weeks and has put pen to paper on a deal until the end of the season.
The Israeli international has been a free agent since leaving Portsmouth in August 2012 and joins in time to face West Brom in the FA Cup on Saturday. The 30-year-old has been training with the Rs for the past six weeks, and Redknapp believes his experience will help them avoid relegation.
“Tal’s a great professional with vast experience, and I’m confident he’ll be a really useful addition to the squad,” Redknapp told the club's official website. “His attitude is first class and the fact he can play anywhere across the back four is obviously a big bonus for us.
“He just wants to play. He’s not here for the money or anything like that. He just wants to come in and do his best for the club.”