Join Tables

Supplying some further information:

Each table currently does not have a team_id - they each only have their
regular IDs.

Secondly, I parse data weekly so there are multiple week snapshops of
each table.. for example:

Week 1 Snapshot houses 120 teams and their data (non-ordered) ids from
1-120.
Week 2 Snapshot houses the same 120 teams and their new data
(non-ordered) ids range from 121-240.
Week 3 Snapshot houses the same 120 teams and their new data
(non-ordered) ids
range from 121-240.
etc.
etc.

This applies to every table I have. In my model I currently show the
current week's data only. I could simply overwrite this data, but I'm
saving weekly snapshots so that people can select previous week data or
data from farther back.

So, there needs o be an associative team_id that is assigned to every
team and so it's the same for every table.. i.e. 120 teams in
alphabetical order with team_ids that range from 1-120. This should
apply to each table.

How do I create the join table to accomplish this?

Thanks.