Hi Narendra,
Try below approach:
1.When user clicks "Add", Enable the text box and at the bottom, have one more button called "Update" ( It is very similar to SCN Reply, where first the user clicks "Reply" , inserting their content and finally clicking the "Add Reply" button at the bottom.)
2. When user clicks "Update", call your oData Service to update the data in back end.
3.Now to display the entire comments from page 1, call oData service to read all the comments, and bind it to a sap.m.List or sap.m.Table in page 2. (Suggestion: You can include a function onBeforeShow in your controller of second page, and call the odata service to read the data, bind the service response to list/table)
Regards,
Meganadhan S
