You can prepare your initial table in your spreadsheet program by specifying in a dedicated column the email addresses of the people you want to send each row to.
Note: If you know that some values are possible and yet not present in your current data, you can use the following trick to have them as a possible choice. Like on the screenshot, you can put these values in the desired order within the columns you want to get an update on (possibly at the top or bottom of each columns). The column containing the emails should be empty for these rows. MasterTable will use these "hint" rows to determine what are the range of values to propose for update and in which order to present them. If there are no "hint" rows with empty email, MasterTable uses only the values that are in the table and the order in which they are shown. The "hint" rows will not appear in the mails that will be sent.