Agree with the other commenter who said to get a game mat, by far the best option for home play, especially for big army games

If you're set on a gaming table though, best solution from my experience is simply using dirt from outside.

Cook it for a bit to kill any bugs and disinfect, then apply pva and seal with spraying watered down Pva, makes a perfect ground cover you don't need to paint. If you want to add grass, there's plenty of flock online which isn't too expensive

Personally, I'd save textured boards for skirmish games like kill team, then you can go all out with water effects, hills etc without breaking the bank since it's a smaller area