Every ability possessed by one or more fairy type pokemon. The generation column indicates the earliest generation containing a pokemon which possessed the corresponding ability (no duplicates).
To make the generation column provide actually useful data, pokemon are listed by the first generation they appear in the series regardless of whether they were fairy type at the time, or whether fairy type existed at the time. Otherwise, over half the abilities would be lumped into Gen 6 alone, making it extraordinarily difficult to pin-point what you are missing.