Documentation:
TablePress Styler

Requires: TablePress Pro or Max.

Horizontal Alignment

Here you can set the horizontal alignment for the fixed columns left header, body and footer.

Vertical Alignment

Here you can set the vertical alignment for the fixed columns left header, body and footer.

Padding

Here you can set the padding for the fixed columns left header, body and footer.

Background Color

Here you can set the background color for the fixed columns left header, body and footer.

Font Styles

Here you can set font styles for the fixed columns left header, body and footer.

See here for more details.