What did this ATC call mean?
They said "TBM" "Three-Bravo-Victor" (3BV). TBM is the aircraft make, a TBM and 3BV is the last 3 letters of the callsign.

The maneuver really isn't traffic avoidance so much as exactly what the controller said, spacing. They need to keep a minimum distance between traffic so having the TBM (a fast aircraft) perform an S-turn allows the aircraft in front of it more time to get further away. 

Usually if you are in the pattern they will ask for a 360 turn, but if you are in a long straight-in and they just need a little bit of spacing, they will ask for the S-turn. For the S-turn approach you would simply turn 90 degrees to the course, then roll 180 degrees to face the opposite direction, then 180 degrees back around and 90 degrees back on course.