Ok fender5190, now I see what you wondering about. Looks to me like the tabber is indicating you should play on only the top two strings here (B and e).
The tuning is standard (EADGBe) so playing all the strings would yield a rather discordant result. If the song used some sort of open tuning, that would have been detailed in the string names. Also, there is not anything to indicate a typical chord. Chords are usually noted with all the relevant fret numbers in a vertical line (or sometimes in parentheses above the tabs).
Since the fret numbers are slightly misaligned here, I would infer that you are to play the notes slightly apart (rather than simultaneously). This looks like some kind of descending melodic riff.
The thing about tabs (and simple chord grids) is that they really only make sense when you already know what the song sounds like. Unlike formal musical notation that can convey tone, tempo, attack, and other subtleties - tabs and chords can only impart a very rough interpretion which relies largely on the player's familiarity with the song to fill in the gaps.
Does all this make more sense now? James
"That darn Pythagorean Comma thing keeps messing me up!"
[url]http://en.wikipedia.org/wiki/Pythagorean_comma[/url]