Create summarized tables with 2 dimensions from multiple tables

Hi velvetine_123 ,

Please try below code:-

SummarizedTable =
VAR _uni =
    UNION (
        SELECTCOLUMNS (
            'Table A',
            "Date", 'Table A'[Date],
            "Category", 'Table A'[Category],
            "Sales", 'Table A'[Sales],
            "Cost", BLANK ()
        ),
        SELECTCOLUMNS (
            'Table B',
            "Date", 'Table B'[Date],
            "Category", 'Table B'[Category],
            "Sales", BLANK (),
            "Cost", 'Table B'[Cost]
        )
    )
RETURN
    SUMMARIZE (
        _uni,
        [Date],
        [Category],
        "Sales",
            SUMX (
                FILTER (
                    _uni,
                    [Date] = EARLIER ( [Date] )
                        && [Category] = EARLIER ( [Category] )
                ),
                [Sales]
            ),
        "Cost",
            SUMX (
                FILTER (
                    _uni,
                    [Date] = EARLIER ( [Date] )
                        && [Category] = EARLIER ( [Category] )
                ),
                [Cost]
            )
    )