Can i get extra sim card tray for my ipad 3?

Try something crazy, like typing "iPad 3 sim tray" into Google.....

Only if it is an AT&T iPad. Otherwise you can't insert a SIM card.

AT&T

ATT

The newest iPad's also have SIM slots for the Verizon, Sprint models and they are sold around the world, not just in the US and not just on AT&T. You are posting on an iDevice that is why you are having the issue with the ampersand.

This is for iPad 3rd generation.

Same thing applies since that is an LTE model and same thing applies as to being sold worldwide.