You can select to use a small caption-size text styling for Dynamic Text blocks in Page Titles.
This size is smaller than the other options for this block type, which are:
Display Heading, Heading 1, Heading 2, Heading3, and Paragraph.
Example - Caption Styling
Example - Paragraph Styling
Setting Caption Styling
To use the caption styling, navigate to a Page title with a Dynamic Text block and click the item's arrow.
This will open the block's setting options.
Click the Style drop down and find and select the Caption option.
Make sure that the Style is set to Caption on the options window.
Then click the SAVE button in the upper right of the Platform interface.
You can then use the PREVIEW button in the left column to see the change.
For more information about working with Dynamic Text and other Content Blocks, see this document: Content Blocks