Snap to line and Snap to Point can someone please explain

I'm trying to create a tune for IMRC delete on 2015 GT i tried to follow a boss 302 file and make sense of the mapped points and distance tables i'm trying to wrap my head around how the different points can blend together see attached screenshot. is the rows i circled in blue used for the snap to line? if so is this how the different mapped points blend when logging? what does snap to point do?Attachment 77899

Attachment 77906Attachment 77907

thanks