How to add more than 3 columns in editable grid?

@ramyad To the best of my knowledge, one of the work around that could best fit the requirement is,
1. Make the paging grid selectable and make sure that the selected row (or the identifier) is saved into a variable.
2. Submit the form to take action on the selected row. (For instance, a button named as 'Update' should be clicked when a row is chosen for update)
3. Perform updates in the next user input task.

An other way you could think of is, to have an excel file upload in place. After filling the excel file with desired values, it can be uploaded into Appian and can be shown in the grid. If the user wishes for any further updates, once again we can facilitate the user to upload the excel and we can parse the excel and show the new values in the paging grid once again.

Let's see if you could get any other valuable suggestions from other practitioners.

Further I would like to suggest to upgrade to latest version if possible, in order to leverage Appian's features.

Thanks for your Response...
The issue is...We want to add a column which is editable...(for instance, I have a selectable paging grid, in that I have made selection, against that I have to provide comment in a editable text field.

@ramyad You could add the column (intended for providing comments) in the paging grid. Initially this column might be blank as it won't have any values until and unless we add some text. Once when you select a particular row, submit the form and navigate to a new user input task where you can update the contents of the chosen row (that is, provide an editable text or paragraph field in which you can provide some comments and update the same in the column of the CDT variable which is chosen for the update). Once when you are done with the update of the chosen row, navigate back to the interface which will actually surface the grid and provide an ability to select row and update it.

I know that the whole process specified above is cumbersome, but until and unless you go for an upgrade in the version, you wouldn't be able to leverage the Appian's features.

I second the answer. Editable grids are not available for old forms designer. So you would have to implement the suggested solution.

Also, I highly recommend applying a most recent version of Appian. Appian 7.3 hasn't received patches or security updates in almost a year. There is quite a bit of risk here.

@Sikhivahans: But here the challenge is, I am going to select multiple items ,against to each item I need to provide comment.
I cant have those many text/paragraph fields,if I have more selections.

@ramyad Understood, I would like to suggest to refrain from choosing multiple items at a time to provide comments against. The reason why I am saying that you should refrain from taking action on multiple items is,
a. The Appian version which you are working on doesn't have a capability to provide editable grid in Tempo.
b. The Appian version which you are working on doesn't have a capability to generate components dynamically in Tempo. (For instance, in the latest versions we can generate components on need basis.)

So stick with updating one record at a time, and this would be the only solution until and unless you go for an upgrade.

Else an excel file which contains the data already present in grid, and an extra column for for capturing the comments should be fine. But I would like to suggest you to go ahead with updating one record at a time as long as the client is happy with it.

And to reiterate what myself or @Myles Weber has said earlier, please do look at the possibility of upgrading the version as this might solve your design issues.