Cables are a genre of knitting that just reminds me of fall and winter. I guess that's because cables make me think of Aran sweaters, which are horribly impractical in the South but still very beautiful and requiring of great skill on the part of the knitter.
For those of us who don't need big fisherman's sweater (or, like me, lack the patience for that much knitting that requires thinking!) a well-placed cable can add interest to a project without a lot of work.
Cables are simply stitches worked in an order other than the way they're normally presented on the needle. Some number of stitches are slipped to a cable needle and held to the front or the back of the work while other stitches are worked. Then the stitches from the cable needle are worked.
If the cable needle is held to the back while the other stitches are knit, you get a right-slanting cable, while a left-slanting cable is produced when the cable needle is held to the front. Cables are typically worked over even numbers of stitches in Stockinette Stitch on a background of Reverse Stockinette Stitch, which makes the cables pop out even more, but they can be worked on any number of stitches in a variety of stitch patterns.
If you've never tried cables before, check out my Cabled Napkin Rings. They're a great way to practice the basics and would look great on your holiday table!