Signature tables define who needs to sign a document. The actual signatures will be added once the document has been archived (frozen) in the SIGN category.
Changing the columns in the signature table
For e-signatures you need columns of these 3 types, the others are optional:
Name: a selection drop down for the user who needs to sign the document
eSignature Date: will be filled with the date when signing the document
eSignature Signature: will contain the token and optionally an image of the signature. The image can be defined in the User Profile