You've probably already foudn where you made the mistake, but for completion, I wanted to explain.

The webpage you just cited was NOT referring to the table when calculating the PAF. In fact, all the information for the example you just stated can be found in the sentence immediately preceding the calculation.

For example, if we know that the relative risk for the effect of smoking on lung cancer is approximately 20, and our surveillance system data tell us that 20% of the adult population of the U.S. smokes, we can calculate the proportion of all lung cancer cases in the population that are attributable to smoking.

If you were to use the information contained in this sentence, the calculation of the PAF using the formula given follows.

Good luck.