What is the meaning of the word "tab"?

Definitions:

A small piece of paper, metal, etc., that is attached to something larger and is used for giving information, fastening, opening, etc. NOUN
- Make a file folder for these documents and write 'finance' on the tab.
A small symbol on a computer screen or website that allows you to open different documents or pages. NOUN
- Move between the pages by clicking on the tabs at the top of the screen.
The small piece of metal, often joined to a ring, that is pulled off or pushed into the top of a can to open it. NOUN
- The tabs from soda cans often end up as litter.
The total money charged in a restaurant or hotel for food, drinks, etc. NOUN
- He kindly offered to pick up the tab.