Brando,
my 2c mate.
Can't seem to get a clear answer as to why some brewers add table salt.
salt (non-iodised) changes the flavour of your beer.
Some add it to the mash, and others add it to the boil.
i add all my water chemistry directly to the mash. this is because if i am adjusting my water chemistry you can bet there is a calcium addition and i want the calcium benefit during the mash and calcium is not very soluble
Salt for flavour enhancement could be added later in the process
Most seem to add about a teaspoon per 23L batch.
Seems to be used in darker beers only, such as ESB's, porters and stouts.
how much you add depends on how much is already in the water you are using and the style of beer you're brewing. I suspect 1 tsp is on the high side for most waters/beer styles
I've found some suggestions that it makes the malt flavour more "rounded" - whatever that means.
"rounded" in my experience is smoother, more mouth filling, less rough grainy edges
Is there any sense in using it if I already use pH5.2 stabiliser?
salt <is not equal to> 5.2 buffer, so there is sense in thinking about using salt in your brewing. they do very different things in terms of process and flavour
Other stuff not asked about.
Do you think your beer needs salt added? or other water chemistry adjustments? enter some in a comp for feedback. chat and give samples to local brewers with more experience. read more about the effect of chemical additions while you're tasting your own beer, do you think your beer could be improved by adding stuff to it?. maybe try some water chemistry adjustments where you would expect to see a lot of difference like gypsum in an IPA
what is your local water like anyway, google your local water board they usually have a typical analysis. you need this as a starting point.
John Palmers how to brew has lots of useful stuff about water chemistry and I always like to recommend it, but perhaps a book called "beer captured" might me of more use to you. it has a couple of appendices with common water additions. gives appropriate additions (in tsp amounts) for different beer styles based on your existing water profile. pretty easy to use.
good luck
keith