A filing cabinet is formal term for a person that exhibits little to no intelligence, provided that they have a functioning brain. Many people mistakenly use terms like "stupid", "retarded" or "mentally handicapped" in place of such a word, but those words are reserved for people without a fully functioning brain.
The term given to the practise of accepting documents for storage (or further reference) when in fact they are just thrown into a pile that is discarded after a few weeks.
Usually the jewish filing system is put into use when documents are "too important" to immediately throw away but aren't important enough to sort for retrieval (as nobody ever asks for them)