How to save table's multiple rows in database

Question

Hi, I want to insert selected rows from table into database, It's asp.net core 3.1 application. 
I'm my view I've populated table from excelsheet now I want to insert the tables data into database, I've a checkbox column to select specific record. 
What I'm doing is creating JSON objects and inserting it in database, but issue is when i have large data the JSON object goes null in controller (I'm using ajax post method here). May be it is due to JSON object length size, below is the query I've made on stackoverflow.

Now I want to insert the selected bulk data in database, any efficient way to acheive this?

https://stackoverflow.com/questions/66924661/max-length-for-json-object-asp-net-core-3-1?noredirect=1#comment118304264_66924661

 

 

Thanks in advance.