When you have created your own graph or table, you do not need to cite it. (The exception to this is if you have published the graph/table external to the university, like if you published a book or an article. When you cite something you have previously published, you cite that resource as if it was not you.)
When you create a graph or table in an assignment, you need to cite the content you put into it. Then you refer to the graph/table in the text.
Be cautious about using someone else's graph or table in your own work. It may be copyrighted and considered a significant portion of the resource. It is best to create your own or describe the pertinent information. Always cite the resource!
