Yes, (I'm a smoker and do it regularly before the wife gets home)...
Sand off the varnish all over and, depending where the table will be used and how you want it to look - dress it with teak oil (best in a kitchen) or give it several coats of varnish if you must.
Teak Oil - Rub down with a power sander held dead flat to prevent hollows forming and use progressively finer paper. Finish off with a really fine paper by hand (I use 400 grit). Then wipe over with white spirit and or a vacuum cleaner to remove all the dust. Then apply three or more coats of Teak Oil over a period of several days.
It is often best to do the sanding outdoors.
Varnish - Prepare with sandpaper as above and use gloss varnish - give it a couple of days to harden and sand with fine paper remove sanding dust and apply a second and then a third coat leaving it to harden each time and sanding and removing the dust each time.
Lastly apply a coat of Matt Varnish as a finishing coat. This will allow the grain of the wood to be seen through a light sheen rather than all the imperfections in the surface being shown up by harsh reflections.
Dressing with oil is much better especially for pine and especially in a kitchen. It also makes it easier to spruce it up the next time it needs doing.
Peccavi
April 2009