Problem Creating a table using columns from different tables (DAX)

Hi, HamidBee 

Calculatetable is not used to connect tables, so the latter code has no effect.

CALCULATETABLE function (DAX) - DAX | Microsoft Docs

Calculatetable and Union function both will create a new table.

Like this:

Table =
UNION (
    SELECTCOLUMNS ( '2020', "values", '2020'[Value], "Dates", '2020'[Dates] ),
    SELECTCOLUMNS ( '2021', "values", '2021'[Value], "Dates", '2021'[Dates] )
)

This table can be displayed in the desktop as a new table, or as a variable table in the measure.

If you don't want to add the third table, you can easily append them in PowerQuery.

Like this:

Below is my sample.