ListOfValues via Context to API

[Karuetl]

I am currently creating list of values in the context variable and pass it to the API 

Problem is there is a limitation with the length of list values i.e. max 2100

I have values beyond 3000K 

How can I handle this 

It's not good to iterate each row data and pass it to API as it takes lot of time 

Any possibility of creating multiple arrayoflist and send it to API