Within the General Headquarters Middle East Force the 2nd Echelon was an office reporting to the Adjutant General responsible for reports of strength returns, casualty reports, grave registrations and disposing of casualties' personal effects. It included Chaplains, Graves, Medical & Dental, Pay, Education and Provost.
This is the annual dinner of the Chief Clerk's department within GHQ 2nd Echelon whose name may very well have been Lockey or Kilgannon, giving their names to elements of the staff whose names presumably are those you refer to on the back.
MaxD