If they used "spackle" to fill anything on the outside you got ripped off!
Spackle is just for filling small nail holes inside!
It's likely splitting because it was allowed to go to long between repaintings.
Any filler used now is just going to fail from expantion and contraction.
As mentioned...
Just a really bad idea!
It would be cheaper and faster to just by a new table.
The only time I've seen this work out is when the guy cut out a piece of 4 X 8 X 3/4" PVC to fit.
It worked perfect, but looked like poop.
I've owned a lawn care company for over 15 years. I've tried the double blades, adding a mulching deck and blades to the mower and it always was a mess. Just cut the lawn at 4" and it will look better and choke out the weeds.
Best that could be expected, except those grade marks that should have been sanded off before staining.
Use a transparent or semi- transparent stain and every flaw will show through and will not last as long.
#1, That's not stucco, It's panels that just look like stucco.
#2, Where's the pictures of the rot?
Your siding looks like Smart Side, the only time I've seen it fail is if it was installed to close to grade.