What element is often found on tables? headers, legend, horizontal axis, vertical axis

headers

Explanation:

A table is the visualization of data by representing attributes or data in series of rows and columns. One important and key feature of a table is the table header. The table header gives a well defined title to use to which table is put to. It can be a "table of age of goats and gender". All tables must be titled with a header in this manner.