Can I eat at a picnic table on Chol Hamoed?

On Chol Hamoed, can I eat at a picnic table? The  proper way is to bring with you like a disposable   plastic tablecloth. Put it over the table. In your  own house, you wouldn't use your chametzic table.   There could be crumbs and things on there.  So, therefore, even if you're going to say,   I'm eating on a paper plate, but things could fall  off the paper plate. Therefore, it's appropriate   to put down a plastic and not to rely on the  fact that you're just going to keep everything   on the paper plate. Similarly, anytime one's  eating, let's say at work, during Chol Hamoed,   if there are others who are eating chametz at  the same area where you are, you should not   eat at the same surface because we're afraid on  Pesach for even a mashul, even the smallest tiny   crumb. So therefore, while we're eating, we we  should try to keep our food away from chametz.