This line:
<div style="width:0px; margin:1px; padding:1px; float:left; width:100%; font-size:100%;">
is styled with inline CSS which you shouldn't use because it overrides the styles in your external style sheet (style.css).
Okay back to basics. Your theme is made up in two parts; the content, which is defined by the PHP files, and the presentation which defined by the CSS file(s). In the PHP files there are XHTML tags, class attributes and ID attributes. The tags, class, and ID can be targeted with CSS. When I want to target the <p> tag to make the text red with CSS, I add p { color: red; } to my CSS file. When I have two paragraphs on a page and I want one to be green and another to be blue I can give the <p> tag a class.
<p class="color1">first paragraph
<p class="color2">second paragraph
I can target these classes with CSS like this:
.color1 { color: green; }
.color2 { color: blue; }
the <p> that has no class added will stay red like you defined before.
In the same way you can add or change a class or an ID to your page2. By changing the class or ID that gives the table the lines, it no longer applies those lines anymore.
If the lines are styled by the tag selector you can add a class and specify that it should have no lines ( .noline { border: none; } )
If this is still all a little unclear, there is an excellent tutorial on XHTML and on CSS on the HTML Dog website. They explain things in the easiest way and they're free. If you take the time to read through the beginner tutorial this will all make sense.