• There’s not nearly enough sunlight literally under the shaded pavilion for that to happen.
• Another commenter pointed out the charcoal dust stain on the pavement to the left, plus there’s an almost perfectly circular ring around the burn site, suggesting heat was travelling evenly sideways around a circular object above, such as a pot or a pan.
• Nobody runs an extension cord over to that corner of the pavilion, the only plug is on the very opposite corner of where this occurred at.

So, my spidey senses still believe that some idiot placed a rack, a pot or pan, and some coals right on the table to cook some food.