It's hard to help without seen any code, could you please turn this into a self-contained REPRoducible EXample (reprex)? A reprex makes it much easier for others to understand your issue and figure out how to help.
If you've never heard of a reprex before, you might want to start by reading this FAQ:
Does have to be input as a table? You could always create textInput() or selectInput() and gather the data that way. Otherwise, I've had success using the package library(rhandsontable) although it can be a pain to get it to give back your data once input, which is why I bring up the input() options.
@Suhasb11, maybe you can check this out! Shiny Contest Submission: Table Editor Shiny App You can entry data from R shiny and click download button to download in csv. I also post some alternative solutions (in replies) that in case you want to implement double clicking as cell modify feature, or you want to have a master file stored in Dropbox. Hopefully this will help!