EmailAddress                         EntityId

12_abc@abc.com::::13_pqr@pqr.com     101
12_koi@koi.com::::13_poi@poi.com     102

EmailAddress   EmailTypeId     EntityId

abc@abc.com    12              101
pqr@pqr.com    13              101
koi@koi.com    12              102
poi@poi.com    13              102

DECLARE @MyTableVariable TABLE
(

  EmailAddress nvarchar(250),
  EntityIDE int
);

INSERT @MyTableVariable(
  EmailAddress,
  EntityIDE
 )

SELECT  concat([EmailTypeID], '_____', [EmailAddress]))), [EntityID]
FROM [dbo].[Email_Addresses] where [EntityID] in

(select [EntityID] from [Entities] where [SourcePrimaryKey] in
    (select [MerchantOwnerID] from [dbo].[Merchant_Owners] where [MerchantID] = 1 ) and
    [EntityTypeID] = (select [EntityTypeID] from [Entity_Types] where [EntityType] = 'MerchantOwner'))

select * from @MyTableVariable

(select [EntityID] from [Entities] where [SourcePrimaryKey] in
    (select [MerchantOwnerID] from [dbo].[Merchant_Owners] where [MerchantID] = 1 ) and
    [EntityTypeID] = (select [EntityTypeID] from [Entity_Types] where [EntityType] = 'MerchantOwner'))

EntityId

101
102
103
104
...