Reverse Running Total Measure per Category/Bin (WINDOW Function) - Avoiding Multiple Tables

Thank you for sharing the model, I have checked and you would need to use Summarize to reshape the data to one row per Category & Utilization bin. 

I have checked and this DAX measure would work on the model if you replace it in Table 1

Reverse running total (%) = 
VAR BinTable =
    SUMMARIZE (
        ALLSELECTED ( 'Table Sum Max 1' ),
        'Table Sum Max 1'[Category],
        'Table Sum Max 1'[Utilisation (%) (bins)],
        "_Count", COUNTROWS ( 'Table Sum Max 1' )
    )

VAR CurrentBin =
    MAX ( 'Table Sum Max 1'[Utilisation (%) (bins)] )

VAR CurrentCategory =
    SELECTEDVALUE ( 'Table Sum Max 1'[Category] )

VAR TotalPerCategory =
    SUMX (
        FILTER ( BinTable, [Category] = CurrentCategory ),
        [_Count]
    )

VAR ReverseCumulative =
    SUMX (
        FILTER (
            BinTable,
            [Category] = CurrentCategory
            && [Utilisation (%) (bins)] >= CurrentBin
        ),
        [_Count]
    )

RETURN
DIVIDE ( ReverseCumulative, TotalPerCategory ) * 100

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