How to design data about a column can belong to the whole table?
Given the tables you have (I'm assuming this structure):


Products
--------
  ID
  Name
  VendorID
  MedicalCode

HelpText
--------
  ID
  Description


I'd suggest adding 2 new tables:


product_help_text
-----------------
  product_id
  help_Text_id

help_text_types
---------------
  id
  description


And changing HelpText:


HelpText
--------
  ID
  Description
  HelpText_type_id


So now, you could have some data like this:


Products
ID | Name      | MedicalCode
-----------------------------
1  | red pills | 445631-XS3
2  | blue pill | 043-PPLE-A

HelpText
ID  |  TypeID  |  Description
--------------------------------------------
1   | 1        | Take 3 times / day w.water
2   | 3        | Verify patient's health card
3   | 2        | check for other drug reactions

helpText_Types
ID  | Description
-----------------
1   | For the patient
2   | For the doctor
3   | for the pharmacist

product_help_text
product_id  |  help_text_id
---------------------------
1           |  1  
1           |  3
2           |  1
2           |  2


product_help_text tells you which text goes with which product, and you can use the help text types to control which text gets seen where (for patient, pharmacist, doctor, drug sales rep, etc...).