You can just use the menu manager, add a link and title for each category.

And then add a menu block.

https://www.tinyportal.net/docs/index.php?cat=97

Hi lurkalot: GREAT idea! for a newbie like me!
At least I was right with my supposing 

Regards
Michael

It's really pretty easy to do.

1: TP admin Click Add Menu icon.
2: Give the menu a name. Example, Download cats.
3: On the page click the edit button for that menu.
4: At top click Add menu item.

5: Title: add a name = Category name or whatever you want.
6: Type: choose Link from the dropdown.
7: Item: add the url to one of your download cats.
8: Save.

Repeat steps 5 through to 8 until you have all your required categories added to the menu.

9: Finally add a menu block, and Choose your Menu from the "Use Menu" dropdown.

Save.

10: Admire your shiny new menu.