Excel needs to have a smart select feature. Select All (CTRL-A) should only select rows/columns that have data instead of the entire sheet (through column ZZ?)
An example of a tasks I am doing. I have say 14 columns of data with 300 rows. I want to be able to select all of those columns and rows to convert them to a table. Select-A would be ideal; however, doing so, selects the entire sheet which therefore converts the entire sheet entire a table (takes a long time to do so). This process warns the individual prior to but would be nice that Excel would either select the data columns or ask,
"You have selected the entire sheet, would you prefer to select the columns/rows that contain data instead?"
This is already supported if selection is in a range of data (within the larger sheet). Ctrl+A will select the continuous range of data the first time you press it, and then if you press it again, it will select the entire sheet.
Kenneth Barber commented
Ctrl + A already does that, but you do have to pay attention to which cells are already selected. If you have data selected and there are adjacent data cells and you press Ctrl + A, then all data cells in the "current region" will be selected. The "current region" is an area of data cells surrounded by blank rows, blank columns, or the edge of the sheet.
I definitely disagree with your suggestions that Excel asks that question that you wrote, since it doesn't take into consideration multiple data ranges on the same sheet.