Microsoft Access activity tracking database (linked to multiple internal/external contributors, external companies)

A MS Access database (table relationship design, forms, macros/vba) with functioning logic (but no nice formatting needed): - Activities tracking (activity description, internal-contributors, external-contributors, external-companies) - Activities can have multiple "internal-contributors" and multiple "external-contributors" - "external contributors" work for "external-companies" - Database user can create/edit activities and add/remove multiple "internal-contributors" and multiple "external-contributors" - Database user can also create/edit activities and add/remove multiple "internal-contributors" and multiple "external-companies" (without specifying which "external-contributors"). - Database user can also search and open an individual contact (e.g. internal-contributor, external-contributor, external-company) to see what activities are linked to them and add further activities. So it includes multiple many-to-many relationships around activities, where data can be searched / entered from different angles. Sometimes activities are linked only to internal-contributors and external-companies, sometimes they are linked to internal-contributors and external-contributors (and therefore also linked to their external-companies they work for). Forms to open/edit should include some kind of comboboxes to search/add/remove contributors or companies or activities as there will be for example 2000 contributors. This is just a prototype to compare the logic/code/approach with an existing database. So no nice formatting is required. But best practice for such a database design should be applied (e.g. no multi-value fields...)