I understand you cannot create a linked server between two SQL Server database instances.
Did you try creating SQL Insert statements for data that is stored in source database table?
Creating a insert script can be a solution of course data is not too big.
An other dummy solution can be creating a new database, copying source table into new database.
Then you can attach database
in the target SQL Server instance and compare these two database objects using T-SQL or third party tools like xSQL Data Compare