Most of the strandlines are less than 20m above present sea-level. I reckon that big storm waves sometimes affect the surface up to a height of c 10m and maybe 50m inland from the shore.
I thought at first that this whole area was made up of a large suite of strandlines or raised beaches, but I quickly noticed that the degree of stone and boulder rounding was not sufficient to justify that interpretation, and the only possible alternative explanation is that this must be a vast expanse of morainic debris laid down during one of the big retreat stages of the Scandinavian Ice Sheet after 20,000 years BP. Sea level must have been higher than it is today because of isostatic loading, but on a rising coast the morainic expanse was not affected by wave action for very long -- the result being a washing out of finer material and a survival of most of the sub-angular and faceted stone shapes typical of glacial moraine.
So -- this is a classic washed moraine landscape. It's probably featured in all the Swedish glacial geomorphology text books -- but I have not had time to check!
Just before putting this post together, I checked out the maps of Scandinavian Ice Sheet retreat stages, and sure enough I see that the outer part of the archipelago in this area reveals fragments of the "Halland retreat moraine complex" dated at around 16,800 - 16,200 years BP. So there we are then- my observations slot very nicely into the established chronology.
Source: "Investigating the last deglaciation of the Scandinavian Ice Sheet in southwest Sweden with 10Be exposure dating", Journal of Quaternary Science 27(2):211-220 · February 2012, by Nicolaj Krog Larsen, Henriette Linge, Lena Håkansson, Derek Fabel