Varnish if you must - I think a kitchen table is best dressed with Teak Oil but I'm an opinionated old ***
To Varnish rub down best with an orbital sander using progressively finer grade of paper & keeping the sander flat to prevent hollows and the movement in the direction of the grain. Finish off by hand with very fine paper - I use 400 grit. Brush & vacuum and wipe over with white spirit.
This is your last opportunity to use oil!
Varnish with a good quality gloss and allow at least 24 hours to dry. Sand lightly by hand with your finest grit paper and wipe clean again with white spirit. Varnish again twice more leaving 24 hours and rubbing down as before. Do not be tempted to use an old paint brush because you may get paint smears in the finish - buy a good new brush and keep it exclusively for varnishing.
After rubbing down the third coat apply a coat of Matt Varnish - this will allow the grain to show and largely remove any reflections from small dents that look so tacky. Wait 24 hours before using.
Oil on the other hand may be reapplied as often as you want and the table used almost immediately afterwards. No varnish to sand off when you want to really spruce (forgive pun) it up.
Unless you really want it dark there is no need to darken it artificially - both oil and especially varnish will resist staining - cirgarette burns are another thing and perhaps the real reason I prefer oil.
Good luck...
Peccavi
June 2009