That would be the listing of deceased family members to be read during the All Souls Saturday Liturgies. The envelope from my parish includes lines on the back to add additional family members as needed. Since the first All Souls Saturday fluctuates with the date of Easter, the envelope date would most likely need to move as well so as to provide time for the pastor to make the necessary updates.
What follows is an explanation from Byzantines.net that includes yet another spelling of the word...
The dyptichs were replaced by official lists of the deceased members of individual families issued by the pastor. These were called Hramoty, from the Greek: grammata , meaning a written letter or document. The list of the deceased members of a family made in booklet form was called a Porn janik, taken from the Old Slavonic: pomjanuti , meaning to remember, and was used at the services for the deceased.
The custom of announcing the names of the deceased during the liturgical services, as stated above, can be traced back to the first centuries of Christianity. Our ancestors as a part of our beautiful spiritual heritage transmitted this venerable custom to us. Every year, just before Meat-Fare Saturday, the families give the lists of their departed loved ones (Hramoty) to the pastor with the request that they be mentioned at the services held for the deceased on the All Souls Saturdays.