Some information some not

I have two tables on one page. One table is just a single column list of names. The second table has scheduling information, but all text based. I have a client who is copying and pasting multiple cells in from excel to the larger table. Only some of the data is saving, but not all of it. Any ideas on why this might be happening?

Is there a limit to how much data will automatically save at one time? Would it be better to create a button to manually save the data?