There is an old travel game in which a player starts, "I packed my trunk, and in it I put…" and names an item to pack. Each player in turn has to remember the list of previous items and add a new item to it. "Grandma's Trunk" is an alphabet game that builds on this idea. The trunk-shaped box holds twenty-six picture cards, one for each letter of the alphabet. The letter is labeled on one side of the card in upper- and lower-case, along with an object that starts with the letter. The back of each card shows the same object alone, without letters. The artwork is cute and whimsical, and every item is easily identifiable (the only exception being T for "towel" - without the 't' clue it could be a blanket or a washcloth). A separate set of twenty-six "Grandma's Riddles" cards offers a riddle for each letter, the answer to which is the same object depicted on the picture cards.

The instructions propose five primary variations, including the classic packed trunk memory game, which may be played alphabetical or scrambled. This game was most appropriate for older children who already know letter sounds and alphabetical order, and scrambled it is a challenge for all ages. Additional games include "What comes next?", in which letter-side-up cards are put in the trunk in alphabetical order; "Grandma's Riddles," in which prompt cards describe the pictures, and children identify the correct picture cards; and "Grandma's Adventures," in which the cards are used as prompts for improvisational storytelling. All of the games can be played with a single child and an adult, or two children, and would be fun for parents encouraging reading readiness; however, they are best designed for larger groups and would be delightful in a pre-K or Kindergarten classroom setting.