How to split a table in SQL Server into two different related tables inserting foreign key? I have a table OriginTable with the following structure

EventID | Date       | Value1     | Value2     | Value3
-----------------------------------------------------------
5       | 2019-10-07 | MyValue1_1 | MyValue2_1 | MyValue3_1
5       | 2019-10-07 | MyValue1_2 | MyValue2_2 | MyValue3_2
5       | 2019-10-07 | MyValue1_3 | MyValue2_3 | MyValue3_3
6       | 2019-10-07 | MyValue1_4 | MyValue2_4 | MyValue3_4
6       | 2019-10-07 | MyValue1_5 | MyValue2_5 | MyValue3_5
6       | 2019-10-07 | MyValue1_6 | MyValue2_6 | MyValue3_6


where EventID is reinitiated every day, but the combination of EventID and Date values provides a suitable unique identifier.

I want to split this table into two tables FirstDestinationTable and SecondDestinationTable like

ID | EventID | Date
-------------------------
1  | 5       | 2019-10-07
2  | 6       | 2019-10-07


and

FirstDstTblID | Value1     | Value2     | Value3
----------------------------------------------------
1             | MyValue1_1 | MyValue2_1 | MyValue3_1
1             | MyValue1_2 | MyValue2_2 | MyValue3_2
1             | MyValue1_3 | MyValue2_3 | MyValue3_3
2             | MyValue1_4 | MyValue2_4 | MyValue3_4
2             | MyValue1_5 | MyValue2_5 | MyValue3_5
2             | MyValue1_6 | MyValue2_6 | MyValue3_6


where FirstDstTblID references FirstDestinationTable(ID).

The purpose of this task is to save storage space since OriginTable is 120MB each day and I want to execute this on a daily basis.

Thanks.
I do not believe you will save any storage space by splitting the attributes into two tables. INT uses 4 bytes of storage space.  A date uses 3 bytes. Say you compress down a million rows to just one value. ( Ex There are 1 Million rows that have the combination of Event ID 5 and date 2019-10-07). You will save a total of 3 million bytes. That's only 3 megabytes. 

You could technically do the same thing you want on the other side of the table; split off every combination of MyValue, create a look up table of them, and then join each on a third table. But don't!

Readability and maintenance are things to consider along side just storage cost. So is your time developing this solution. The current 10/7/2019 cost for Azure SQL database storage (past your 32gb of free data) is $0.138/GB/Month. After 3 years of every week gaining a full GB of data(Total storage is now 156gb), you will have only spent a TOTAL of $1,679.18.