I managed to obtain this kind of table layout:
fixed – dynamic(50%) – dynamic(50%) – fixed
http://jsfiddle.net/ihtus/ksucU/

But how do I get this kind? fixed – dynamic(30%) – dynamic(70%) – fixed

Here’s my CSS:
table {
width:100%;
border-collapse:collapse;
table-layout:fixed;
}
td {
border: 1px solid #333;
}
Like this:
http://jsfiddle.net/7dSpr/