Please check what all modules are in use/active/installed in your EBS instance. (adutconf.sql -- can be used to check installed modules and from front end using OAM also we can check)
Relevant objects of installed module must be in valid state. If installed module objects are invalid then better to check what errors you are getting when you compiled them manually and this way you may get exact cause of it.
The modules which not in use and you see invalid objects then I believe that can be ignored.
Apparently, the above object tables are basic installed modules like PO or Inventory (MTL).
So I assume they are needed? Or do the forms specifically show the invalid table error when they accessed an invalid one?
Or will I assume that the above tables are not needed since the user did not show any invalid forms error when they do transact business processes?
I am confused
Forms specifically may not show the table details.
If a user getting error message while accessing forms there may be other issues and in the error stack we will get details of the same.
All tables of installed module are very much needed. If forms having issue then we can consider to regenerate forms executable using adadmin and log file will record the details of errors if any.
You try to compile them manually and check for errors which help help identifying exact cause of the error.
SQL> Alter package owner.packagename compile;
subsequently after completing above command run below command to see errors.