How do I lock tables in html

Alright here is the thing I have no idea how to lock tables in dreamweaver/html/ so everytime i make a bunch of table to keep photos in the right places, well you get their purpose, but i wanna know how do I lock them so when i insert text they don't expand, this may be a stupid question but I have been away from the internet and Dreamweaver for a long time, and have forgotten mostly everything i knew at one point in time.

-Shades,

P.S. Thank you to those who respond and try to help :)

Well design has evolved alot... You may wish to looking into XHTML and designing without tables.

However, to fix a table width, you do just that, you give it a set width (each cell) and it shouldn't expand.

Thank you very much, for that. I shall start looking at Xhtml as soon as I am done this site. So if i give it a set width it won't expand? thank you for telling me.