Different way to insert data to a table?

Is there a way to insert data into a table without table.insert? If I insert data into the middle of table, it pushes all the data after it up, and I want to avoid that. Reason being I have a master computer that will be connected to other computers. Everytime the sub-computers turn on the first thing they do is a transmit a message to "register" themselves with the master computer. All it does is take the sender channel and the message to use as the key and value, respectively.

You can set the value of a table simply by assigning a new value to the index you wish to change:

myTable[key] = value

I always overlook the obvious, thanks.