Basic HTML Problems on Wordpress

Hey everyone i'm going crazy with Wordpress. I've been trying to style 2 tables with some simple spaces using the
tag but everytime i switch from the HTML editor to the visual one wordpress just hides the code. I even tried to use some roles plugin but well i'm the only user on it so it did nothing.

Here's the link of the table :

http://adocicarte.com/adocicarte/sabores/

As you can see on the column "sabor" it has a space on top and above the bottom so the text doesn't look to close to the borders. I've been trying to do the same with all the other columns. But i'm going crazy today with wordpress.

The same applies here:

http://adocicarte.com/adocicarte/precos/

But i guess that if i find a way to properly program the "
" tags or some way way to give "space" i can edit the 2nd table.
Any help?