The chart must be pre-Columbus SLX, as it's not included....
I suspect it's not that much lighter than SL. but I notice that as I suspected, the SV980 tubing is quite near to what Reynolds 753 weighs..... So it's in good company weight-wise.
I also noticed how really light the best Tange and Ishiwata tubing really are.... So light! Were they special track/keirin tubesets never used on road bikes??