Is it possible to change the style of Table of contents?

Yes, but using the buttons at the bottom of your screen capture marked Settings and Info:

Settings allows you to set the options for the following:

Style

Select Overlay to overlay the TOC panel on the main movie panel. Ensure that the contents of the movie are not hidden when you choose this option. You can use background transparency to achieve optimum results for slides with overlay.

Select Separate to display the TOC panel separately from the main movie panel.

Position

Left or right position for the TOC panel.

Background

Background color of the TOC panel.

Default

Background color of the TOC menu.

Active

Background color of the active TOC entry during run time. During run time, the TOC entry corresponding to the slide displayed is highlighted in the TOC panel. This entry is called the active TOC entry.

Rollover

Background color of the TOC entry when the user moves the pointer over the entry at run time.

Gradient

Color gradient for rollover.

Heading

Background color of the header and footer.

Outline

Border color of the TOC menu.

Alpha

Transparency of the background of the TOC menu.

Width

The width of the TOC pane in pixels.

Info allows you to....

Enter the details of the author or company in the respective fields.

Click Project Information to use the information that you set in the Project Information menu of the Preferences dialog box. The information from the Preferences dialog box is added to the corresponding fields.

Click Clear Information to clear information that you have entered in the different fields.

Select Auto Preview to have the preview panel reflect a change as soon as you complete that change in a dialog box.

In the Photo section, click the browse icon to select an image to display on the panel. This image can be the logo of your organization, or a snapshot of a prominent slide in the project.

To change the character format for the project information fields: Click Font Settings to specify the font style for the project information.

     a Select the field from the Font Settings list.

     b Select a font family in the Font list and click on a style: regular, italics, or underlined.

     c Specify the size and the color for the characters.

Both of these options appear in the Captivate Reference PDF under the heading "Customize the Table of Contents (TOC)."