Gary - I mean from side to side to get the proper width for the track. scoot the straight edge over just enough for you to get the width you need. you can also wrap some 40 grit sandpaper around a piece of 1/2" wood and sand it by hand.
if you cut the groove too wide, use Bondo body filler. if you cut it too deep, thickened epoxy in the bottom of the groove and the track pressed in even with the wood until the epoxy sets, then install the screws. if it is a wood table, I run the orbital sander over all of it.
looking forward to seeing your new table !!