3D Data - 2 Inputs 1 Output Table - Rearranging and Curve finding

Hi, I have to following data:

NAN   InA1   InA2   ..   InA4

InB1  Out11  Out21  ..  .
InB2  Out12  Out22  ..  .
InB3  Out13  Out23  ..  .
.     .      .          .
.     .      .          .
InB30

This is my table. 'InA' and 'InB' are the measured input data. 'Out' are the output data.

Basically I want to calculate a function like:

Out = f(InA, InB)

How can I do that ? I think I will have to rearrange the table ?

Thanks