What is an NTAP when referenced in a NOTAM?
The Notice to Airmen Publication is an FAA publication, currently available in PDF or print form, published every 28 days. The NTAP contains airway, airport, facility, procedural, general, and international NOTAMs. As voretaq7 notes, this includes long term NOTAMs that a flight service brief won't include if you don't ask. There is also a section with graphic notices, including general notices, special operations, airport and facility notices, and major sporting and entertainment events.

That last section is the one relevant for the NOTAM listed above. This lists information and procedures for any airports affected by special events, which is nice to have in one place rather than looking up long and complicated NOTAMs for each airport. For example, the Masters Golf Tournament referenced in the NOTAM above has a section in the NTAP, affecting airports AGS, AIK, DNL, and HQU. The information includes preferred IFR arrival routings, potential for holds and VFR arrival delays, departure procedures, preferred IFR departure routes, IFR overflights, and VFR arrivals/departures to/from DNL. There is also a special schedule for the tower at AGS, and a temporary tower at DNL.