Rice tables are useful in so many ways. You can talk about texture and color, hunt for missing objects, or just let your child get their wiggles out with sensory play.
I recently made colored rice for a program and used this recipe from Paging Fun Mums. All it takes is some food coloring, vinegar, rice, and baggies. I was amazed how fast the rice dried and how well the color stuck to it.
When you're done, mix the rice together into a plastic bin and hide your child's toys in there. Make it a dinosaur/treasure/train hunt!