what is slab reefing
Those "reef points" lines on your sail are not what you hank your mainsail in when reefing. They are only to neaten up the mainsail on the boom.
The only real stress''s when reefing should be on the clew (at the end of boom) and at the tack (near the goosneck - typically and simply tacked down with a reefing hook attached at the gooseneck)
Go through the archives -- many times its been explained on how to reef. Basically the easiest reefing system just has a reef hook and only a reef line for the clew:
1)Drop Main halyard to set level of first reef (People mark main halyard with indelible ink)
2)Attach Reef Tack to reef hook.
3)Pull in clew reef point (at end of boom) and make tight.
4)Then tighten up on the Main halyard and away you go.
You can neaten up the look of the sail with those 4 reefing lines in your sail. Loosely tie around boom. Tie with a reef knot (square knot).
The reef stress should not be on those 4 reefing lines in your sail, they are not meant for that type of stress and you could rip your sail.