Mix some wood glue in water with a drop of dish washing soap use a old spray bottle to mist the flock. It will wear off. This should help it last longer.
Note* Many PVA glues contain a white filler. This is not a problem until you use it for something as large as a table. The filler will dry and form rings much like the salt rings that form on clothing in hot dry climates. It probably won't show when you paint the PVA on the table to attach the flocking. It will show if you use the mist method. So use wood glue.
I use hair spay for trees all the time. It may attract dust on a table top.
Please post a photo.
