I suggest you to press F12 on your browser, then goto the option to find that portion of HTML, you will see what class is being applied , then you can change attribute so as to know how to fit the content.
Can you confirm what Document Standard you are using in your browser? I also agree with Fernando Hunth that the class will need to be inspected. However, you should quickly be able to see what class it is in the Forms Designer (when you click on the control, the class will be listed in the ribbon).
One thing I'd look at is the sizing of the control itself. I'm assuming those are Calculated Value controls, so I'd look at font-size and the overall size of the control.
Do you see a difference between a published form and form in preview mode?