Forecasting using multiple tables and columns

I'm using a forecast in cell J17, but currently it's only looking up 1 column of my table, and I can't figure out how to get it to select which table to pull data from.

PHP Code: 

=FORECAST(T,OFFSET(O7:O21,MATCH(T,Temps,1)-1,0,2),OFFSET(Temps,MATCH(T,Temps,1)-1,0,2)) 


The way it works is:
1. pick material (and it looks up the correct table)
2. pick Class (150, 300, 400, 600, 900, 1500, 2500)
3. enter temperature

boom...you have the correct pressure from the table selected and the class, even if it's a temperature between the ones listed in the table.

all the table have the same classes and they all line up in the same column

If I've understood:

Formula:

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note: the reference to FClass in your named range needs to be adjusted from O6:S6 to O6:U6

that works... but when i try and add my external table links it doesn't

PHP Code: 

Copy of working formula                                            
FORECAST(T,OFFSET(INDEX(INDIRECT(Table),2,2),MATCH(T,FTemps)-1,MATCH(Rating,FClass,0)-1,2),OFFSET(INDEX(INDIRECT(Table),2,1),MATCH(T,FTemps)-1,0,2))                                            
                                            
Added Colors to make sure everything matched                                            
FORECAST(T,OFFSET(INDEX(INDIRECT(Table),2,2),MATCH(T,FTemps)-1,MATCH(Rating,FClass,0)-1,2),OFFSET(INDEX(INDIRECT(Table),2,1),MATCH(T,FTemps)-1,0,2))                                            
                                            
added link to external tables            doesn’t work                                
FORECAST(T,OFFSET(INDEX(INDIRECT(Table),2,2),MATCH(T,'BDD Library.xlsm'!FTemp)-1,MATCH(Rating,'BDD Library.xlsm'!FClass,0)-1,2),OFFSET(INDEX(INDIRECT(Table),2,1),MATCH(T,'BDD Library.xlsm'!FTemp)-1,0,2))