Duplicated web page contents

Hello,

If an html table containing the same text was required on every page of a website is there any way of creating an external file (containing the table and contents) that every page where the table is required can link to. This way the table and contents only have to be created once instead of possibly hundreds of times. 

For example, I am creating a website that contains about 500 pages. On every page I have my email address within a table. When I change my email I have to update every page manually. I am envisaging a way of creating an external style sheet (or similar) containing the email address within a table. I then only need to change the external page and the other web pages will be automatically updated. Does such a thing exist?

Thank you very much for your time, Kind Regards John