You can access all your Favorites offline.
How to add tabs to Favorites?
To add a tab to your Favorites, tap the heart icon in the top right corner.
Note: You need to have an Ultimate Guitar account to be able to add tabs to Favorites. You can create an account in the Account section of the app.
All saved tabs in "My Tabs" folder are upload automatically, so you don't need to do it by yourself (see attached picture).
Note: offline loading can affect the speed of the app usability, please wait until the uploading is finished and your patience will be rewarded.
Related articles
[iOS] How can I contribute tabs?
[iOS] How do I find ukulele/bass tabs?