My kids did this today. It's an entire bottle of table salt.
When I saw it I tried very hard not to laugh, even though I was annoyed at the mess. This is because my mom often talks about the time she found I had poured an entire bag of sugar on the floor, and then I peed in the middle of it.
I was relieved my kids didn't pee in it (which could have been possible as we're on day 2 of potty training Abby).
What goes around comes around, eh!