DAX that looks up value from another table2 and return data where date in table2 <= date in table1

ouma , Try like

new column in table 1
=
var _date = maxx(filter(Table2, table2[Date] <= table1[Date]), Table2[Date])
return
maxx(filter(Table2, table2[Date] <=_date), Table1[Exchange Rate])

Thanks Amitchandak for your quick response. Your DAX helped me a lot, I improved it as below and it worked

VAR _date =

        TOPN (

            1,

            FILTER (

               Table2, table2[Date] <= table1[Date]

            ),

            table2[Date],

            DESC

        )

    RETURN

        MAXX (

                _maxDate,

                Table1[Exchange Rate]

        )