buttons buttons buttons
If you have buttons on a tab, it could be called a group of buttons. It you have multiple tabs with buttons, you have a group of tabs.
A group of related buttons is called a panel or a bank.
Buttons are sewed onto cloth
The buttons on a trumpet are called valves.
powerpoint buttons
A sweater that buttons up in the front is called a cardigan.
keys
The keypad.
More then likely they are just called keys
Simon says
It's called Koumpounophobia.