Possible Clues:

• Computer key
• At the interval, drinking place used by secretary?
• The biggest typewriter key
• Largest typewriter key
• One often gets depressed, producing no letters
• Longest typing key
• Box opened by one soft key, one that breaks
• Alien drinking hole?
• Typewriter part depressed in order to leave a gap between words
• Heavenly refreshment-room for typists?