Capture entered data into Excel on several remote tablets - transfer by wifi into one master console

I have 6 users within the same location but on separate tablets. They will have a basic Excel grid of up to 60 rows, with 4 columns of data per judge - into which they need to enter any notes that are applicable as well as allocate a score per line of data if applicable. Not every row will have a score or a note. I want to have the ability for them to complete their judging task, complete with notes and numbers, then have the ability to submit their notes per page at a time by clicking on a submit button. They judge over 3 days and across 16 categories. Each Judge will only submit 1 page (the same page as they will all judge the same things at the same time) at a time as it is completed. I want only 1 page per judge (x 6 judges) to be submitted at a time. The data they enter is then received my my master PC, and grabs the data per page (according to what they were judging, i.e. their page id needs to match my master page ID) that they have entered and puts their judging data into the correct field, together with their notes and scores (ie, it matches their name, and drops their unique data into their unique user id field). The rows of data need to expand to allow input from all 6 judges and ideally grab their ID initials so that comments can be attributed per judge. All of this must be transferred by WIFI instantly once they hit submit, so that my master can auto tally all 6 sets of results as they come through. A backup option using another transfer method must also exist in case WIFI or software glitches occur. Notes - this needs to be able to be expanded to add additional tablets/users as required. Constant auto backup feature must be added to software on tablets - this data cannot be lost - critical. Speed of transfer once submit is hit must be instantaneous. Data from user Tablets bust match to unique user columns in master Excel Macro, then cross reference to corresponding rows, as well as extracting user comments per row and stamping comments with user initials of some form of identifier.