Charting file template to clear old data, paste new data and update chart

I want to create a chart(s) in excel that references data on a worksheet. Column A is Time, columns B thru O are Temperature and Concentrations. I only want to have to create the charts once, after the first of a series of tests then save the file as a template. For subsequent tests I want to be able to clear the data in the data sheet and then paste the new data in the data sheet. The new data will always have the same number of columns but the number of rows will always be different as we never know how long a test will last. I want the axis to auto scale because one day we may start a 8am and the next at 1pm.

"Yes, you can do all that pretty easily".

I mean, what's your question?

How do I make excel rescale the axis if the data I deleted had 5000 rows but the new data has 3000 rows? Or the other way around?