if they are for something than what, could you put Arduino accessories?
If you are talking about the 7 unpopulated thru holes at the bottom of the main board directly below the SD card on the brain board, some of those pins are the i2c bus to which you can attach an unlimited number of peripherals and communicate with them via the “wire” library (see wire.h). Power on those pins also.
so you could add a camera there
I doubt i2c could be used for a camera… the data rate is too high. Adafruit has an i2c thermal sensor camera though.
what about a keyboard or radio antenna