Krylon matte varnish is what I use for my models and terrain. keeps grass on just fine.
my hardboard game table that is flocked was done using watered down PVA and then matte sprayed over as a topcoat, and flakes off. especially when the cat rolls around on it...
so I would say that pva glue isn't the bees knees for keeping this stuff down
I typically super glue my static grass on, and then matte spray over it as a topcoat, and it stays on fine.. super glue for whole table will be hard to do, unless you get a nice big bottle of cheap super glue... but you'll probably end up like charlie from its always sunny by the time you're done, unless you do it outdoors
lol