What? Protect it from what, exactly?

tatts,

From food and drink spills that could potentially occur.

Area rug on wall to wall carpet is acceptable. The Ikea option is great. Just make sure it is big enough for your table/chairs. To determine the right size, you will need to measure the amount of space the table + chairs take up. To do this properly, you will place the table and the chairs. Then you will pull out ALL THE CHAIRS as if people where about to sit down. The amount of space you NEED to pull out the chairs and then sit down is part of the equation.

Once you have pulled out all the chairs, you will measure the length and the width of your set up. You will then add 3" - 6" to the length and the width...this is so it looks 'right' if the chairs are pulled out.

Good. Now that you have done your homework, you will go out and find an area rug with those measurements (or something as close as possible...bigger is better than smaller).

If you are getting an area rug to lay over carpet in the dining room, I suggest you get a rug with a pattern. It will add interest to the area and will hid possible food and drink spills.

Check out Chilewich floor mats , when they get dirty hose them off and really wall to wallcarpet is so yucky after awhile maybe plan on another type of flooring down the road.