In javascript table structure how can add dom element or image with text on the table cell

In javascript table structure I already created my table and put my data . However I also need put multiple colored circle but I couldn’t.

I already defined colored circles for legend part (which show colored circles meaning ) I can use them or I can use a image .it is not important. I just want to see this structure.

I just simulate with excel in order to make understand better

I directly try to put my circles but only show “object HTML” text . Please help me, My javascript background is not good.