Merve, nobody is going to kill you. But you might find in the near future that you will want to shoot yourself if you have to go and change your pages. If not, more power to you. The idea of web standards is to make things easier for you, not to give everyone else a reason to mock you. If you are comfortable with using HTML the way you do, good for you. That's all that matters.
The idea is to get away from using width, align, empty cells, and blank gifs to position your data on the page. If all you are using tables for is sectioning off your website to position all the elements, that's what web standards are attempting to get you away from.
Instead, you should use <div> tags an use CSS to position them on the page using margins, padding, borders, etc.
If you are pulling a bunch of data from a database and need to display it in tabular format, then by all means, use a table. Then you can use CSS to format the data in those tables, as well as the table itself (including widths, padding, colors, fonts, and more).
An example is my sample page where I pull information from my database about my tables. I put the data in tables and format the fonts and colors to make it easy to read. However, to do the tabs on the page, I am using CSS on <div> and <span> tags, NOT tables. If you look at the HTML source of the page, you'll see that it is relatively clean and easy to read.
