How can I position divs inside a table which centers when user resizes the browser?

I’ve my website made up in a table. I want to position text over some images. I did this by positioning divs.

Everything was great however I set my margins as auto as I want the page to center when the user resizes their browser. Obviously if divs are set to a specific position they’ll stay and not move with the rest of the content.

I got around this by setting my margin-right: auto, and then inputting my margin-left with pixels.

My problem is sometime when I open the page everything is in the right position, other times the text has jumped up or down.

What is the right way to do this (keeping in mind my main layout is in tables not divs), I can’t seem to find any correct help on the internet?