OK, wenbedma.
If you are learning at w3schools.com you will stay on target. There is no better. htmldog.com is also excellent and is a little easier to follow at times for people just learning.
Perhaps you used the word "table" when you were only referring to the column or something, not really using the table tag in html. But here is the explanation.
In the past people used tables to lay out their pages. This was before css. Many of the tutors on the web are very old and still teach this. The two mentioned here do not.
To show the difference, if you lay out your page using tables and you decide you want to change the font or color in your headers you would have to go back to every single one on every page and change the color. If you have many pages done you would have a massive task for even a small change.
If you use css to do the layout and styling on your page you would have a quick and easy fix. You would open your css file, write one line that changes all the headers, or all the headers of a certain size. Done.
When we say tables are for data, we mean that if you have information that requires columns such as an address list with columns for name, street, phone, etc. then use a table. But for laying out the page use css.
With css you divide your page into sections with the <div> tag. You give each one an id in the tag. It is simple: <div id="leftcol"> or whatever name you want. Then with css you will tell it to go to the left or right, center or whatever. Much easier and effective than html tables, as well as being so much more flexible.
You don't have to know much html before going on with basic css as well. All this may be a little confusing at first, but I am sure it will soon make sense. Just relax. You will have a lot of fun with it as you go along.