Is it possible to attach a description field to the records in INFORMATION_SCHEMA.TABLES?
Use extended properties.  It's not in the INFORMATION_SCHEMA views but it will stay attached to that object.

I wrote about it in detail here: https://sqlstudies.com/2015/05/18/extending-your-metadata-with-extended-properties/

But here is what it would look like attached to a User:



Here is how you would query all of the extended properties for users in a given database:

-- View the extended properties
SELECT ep.*, dp.name FROM sys.extended_properties ep
JOIN sys.database_principals dp
    ON ep.major_id = dp.principal_id
WHERE class_desc = 'DATABASE_PRINCIPAL'
GO


The same thing will work for pretty much any object in SQL Server.  Obviously you'd want to modify the query somewhat but that should be pretty easy.