Firstly, I have a client table with multivalued attributes:

After turning the conceptual design to logical design, I have another table called Contacts for the multi-valued attribute:

The question now is I have to do normalization on Contacts table but I have no idea how to do it. Based on my understanding, 1nf and 2nf have passed. But I am required to do at least one step of normalization. So how can I do 3nf for Contacts table?

Client Client_ID {PK} Client_name Client_address Client_phonenumber Client_interest Contacts [1..*] Record No Date Type Content Date_First_Purchase Latest_Purchase_Date Invoice_number {FK} Client Client_ID {PK} Contacts has 1...* 1... * generate Client_name 1...1 Client_address Client_phonenumber Client_interest Date_First Purchase Contacts_Record No {PK} Contacts_Date Contacts_Type Contacts Content Client_ID {FK} Latest_Purchase_Date Invoice_number {FK} Client Client_ID {PK} Client_name Client_address Client_phonenumber Client_interest Contacts [1..*] Record No Date Type Content Date_First_Purchase Latest_Purchase_Date Invoice_number {FK} Client Client_ID {PK} Contacts has 1...* 1... * generate Client_name 1...1 Client_address Client_phonenumber Client_interest Date_First Purchase Contacts_Record No {PK} Contacts_Date Contacts_Type Contacts Content Client_ID {FK} Latest_Purchase_Date Invoice_number {FK}