My mother lent me a wonderful book on Irish crafts, and in it I found the meanings for the traditional cable patterns.  I think it is important to know what we are knitting! They usually relate to fishermen's lives, sea, earth, sky, marriage, and sons to take his place.
Starting second from top left, the Marriage Lines, or Crooked Road is a zig zag stitch, depicting the ups and downs of married life (usually shown running from shoulder to the hem of the garment).
The Tree of Life, middle row, second from the right symbolizes a long life and sturdy sons.
The Irish Moss, (seaweed with medicinal properties, also used for making blancmange) represents wealth to fisherfolk. The Honeycomb bottom right is a tribute to the bee, which was considered a lucky omen if fishermen saw them before going out to sea.
cable and rope stitches are of all types and represent the sailor's ropes, and the Diamond, usually formed in Moss St represents wealth. 
For more information you'll have to buy the book, 'Traditional crafts of Ireland' by David Shaw Smith, Thames and Hudson.