The show's seventh season finale is set to air May 19.
The comedy about American office life follows Michael Scott; the role is played by Steve Carell, who will soon be departing the series. Guest stars on the finale are speculated as potential replacements, although NBC has not yet made any announcements.
Ferrell (You're Welcome America), who plays a branch manager from the home office, will end his multi-episode arc in the season finale.
Tate will be appearing in the Shakespeare comedy Much Ado About Nothing in May 2011. Spader was last seen on Broadway in Race.
"The Office" airs on NBC Thursday nights at 9 PM ET.