These two columns were each given a width of 100 pixels. However, because the content in the lower-right cell exceeds 100 pixels, the left column is getting squished.
You just got acquainted with the three finicky rules of cell widths. By now you're probably wondering how you can get around this quirky behavior.
For example, let's take a look at the table here. Each column was given a width of 100 pixels. However, the text in the lower-right cell causes the left column to get shortened so that it's less than 100 pixels.
The most precise solution for keeping cells from getting squished like this lies within the glorious and renowned spacer GIF.
To learn more about the spacer GIF, click the Next button.