I have the following tables: reports, standards, elements, tables, items.
* One report has many standards.
* One standard has many elements.
* One element has many tables.
* One table has many items.
[...]
I see that many-to-many relations exist between all of the tables but I am not able to clearly visualize.
From my perspective the fundamental decision you need to make is whether to indeed deal with many-to-many relationships or just deal with one-to-many relationships. In the later case you have 5 entities and 4 relationships and thus you will have 9 tables. If you can force one-to-many relationships then you only need 5 tables, with the four "right side" tables having a FK to the corresponding "left side" table.
Personally, I would go with one-to-many relationships and just "clone" anything that is going to be the same from one year to the next.
