I don't know how to delete tabs that I saved previously and no longer want. How to I delete them?
You can usually right click on something and make a choice to delete it.
Saved tabs would I guess loosely include
I guess it would be app-tabs that you are talking about since the don't leave much room for those who have the tab[x] on each tab.
How to close a tab including an app-tab, some methods
The third method is how you closed tabs prior to Firefox 2 and remains one of the best ways before things were made more complicated with wider tabs, left horizontally scrolling tabs
The setting in about:config for browser.tabs.closeButtons set to 3 to place the tab close button at the far right of the tabs bar.
Mentioned in step #35 in the following
You can force 5.0 "compatibility" with the "Compatibility Reporter" extension, or with extensions.checkCompatibility using about:config. Use at your own risk.
Closing a tab so it is not saved for next session as in "Restore Previous Session" is simply to close the tab. As far as tabs saved in History goes there is limit they will simply roll off.