For the Geniuses (Please

):
I have a pretty little Spreadsheet now that is user friendly, locked cells with formulas, conditional formatting in red if employee checks in late, etc. ....but a couple of problems:
1) Takes a little over 4 minutes to open and calculate.
BTW, it says Calculating 4 Processors and slowly goes through the % being calculated.....as I wait.
2) I need to allow for additional entries I increased the lookup range to allow for additional entries as the year progresses (Probably the reason for problem#1)
ie: 150 employees, * 190 workdays I increased the range from a1:f1256 (current data that I'm working with) to A1:F29000 (allows for remainder of the year as data is
added) ....I'm wondering, should I convert the data to a table?
3)If I do convert to a table, how do I fill the formula relating to the Data Table, It goes to the next column as I fill to the right.....