Hi Chandler --
If I understand your question, you are in Surveyor, you've made up a consist of 100 coal cars and want them all to start fully laden with coal when you jump into Driver. Correct?
If so, use the rolling stock flyout to load one car. In the flyout there is a large icon in the top left that looks like a circle with three cars and an arrow from one to another - "Copy to compatible vehicles".
Click on this icon and all the cars in the train will load, assuming they are the same type of coal car as the one you have loaded.
Tell us if this works for you.
Phil