Hi Gulfer,
It is possible to achieve the lookup table interpolation/extrapolation techinques by using a Mux block and a 1-D Lookup table block after the output of the two 2-D Lookup table blocks. The 1-D Lookup table block was enhanced in the R2020b release to allow Table data to come in via a signal line to an input port on the block. This can be done by setting the Source dropdown of the 1-D Lookup table block to 'Input port' for Table data. The output of the two 2-D Lookup table blocks are fed to the Mux block and then sent to the Table port of the 1-D Lookup table block as shown in the image below:
Note: The 1-D, 2-D and n-D Lookup table blocks started supporting Breakpoints and Table data via 'Input port' starting in the R2020b release. If you are using a release earlier than this, a similar solution can be made by replacing the 1-D Lookup table block by an Interpolation Using Prelookup block, which has had the 'Table as input port' support for many releases now. Hope this information helps. Please feel free to comment if you have any other questions. (The model .slx is attached with this answer).
Thanks,
Omkar
