How to prepare and send all the records(Updated | Not Updated | Inserted) of the REST model as a JSO

I have created REST webservice to read a static resource and return a list of records to SKUID REST client,

My problem is, I want to send the entire JSON string to my update (POST) method.

when I say req.requestBody;

     RestRequest req = RestContext.request;    
      system.debug('  req '+req.requestBody); 

I get only the edited cell value as a BLOB.

How could I send all the table values at once in a JSON string on save.

REST update method in SKUID;

below is my JSON string in Static resource : I want the same string to be formatted in SKUID before calling the REST update,

“detail 1”,
"detail 2 "
“detail 1”,
"detail 2 "