To make a decision you must answer some questions: first, there are dependencies between rows in that big chunk of data?

Second, what do you want to do if a insert fail? Rollback all the inserts, just keep going and create some sort of alert/logging?

Third, there are performance issues? can I run a batch overnight? That data must be persisted ASAP?

I don't thing a big blob/string is a good option because you ill need to parse/deserialize that (sql side) and, in general, putting that kind of logic in a SP(or whatever) is not good for performance, reliability and maintenance.

Search for transaction control and (maybe) stage tables and (maybe) integration strategies.

You can end doing something like:

procedure insert raw data

1- begin transaction

2- loop(insert in stage table)

3- commit tran

procedure process stage table

1- select no processed data from stage

2- loop in

3- begin transaction

4- process and persist data

5- if ok commit, else rollback

6- log results for that "row"

7- end loop

But off course that depends on your requirements.