You can create 7 partitions, each with one slot. Then you would need to create 7 jobs and point each job to the appropriate partition.
Just a word of caution with partitions, if your Overwrite Protection Period or Append Protection Period are not set correctly, then on the following week, the jobs will be unable to find a tape to write to. It will prompt you for a scratch tape. If the scratch tape is not mounted, the job will fail, even when the tapes in the other slots are available.