Well believe it or not, Mme E and I worked on a table with 6 white heat stains from hot plates and made incredible progress.
We used heat ! yup ! It's true !
We took an iron, made sure it had plenty water in it, and set it on the highest setting with steam.
With a white towel over the spot, I quickly ironed the area, lifting quite frequently to get the bursts of steam going. Once done, Mme E, wiped it quickly. And we moved to the next spot.
So today I wanted to try it on a table son #1 got from the road side pickup.( even tho it's going to be painted)
I used no towel at all... just the iron on steam setting.
It was a great success ! Works amazingly ! We might have to go in business .... in a month, after she retires. "C & E hot stuff "
Here's the before and after.