Choose your stain. Wood stains range in color from opaque to clear. Consumer Reports' Web site notes that opaque stains last longer than the clearer stains; however, they also cover up the wood grain, much like a paint. Semi-transparent stains may contain very little pigment or may be nearly opaque. Select the stain based on your desired level of protection and finished look.
Wet the table thoroughly with a hose. Let it dry completely, waiting several days before beginning the rest of the process. Wetting the table before staining will help the stain soak into the wood better.
Sand the table gently. Use 220-grit sandpaper to smooth your outdoor table, sanding with the grain. Brush off any dust or debris that results from the sanding.
Apply stain, using a foam brush. Go with the grain of the wood. Wipe off excess stain as you go with a clean, soft rag. You may wish to wear rubber gloves while working with the stain. When working with a chemical substance, be sure to work in an area with plenty of ventilation.
Let the stain dry. To achieve the color depth you desire, you may repeat the staining process, again wiping off excess stain and letting the table dry completely.
Seal the table with a clear water repellent, if desired. Use a foam brush to coat the table with a thin layer of the clear water repellent. This step may not be necessary if the stain you purchased also included a water repellent.