I was unaware of these two keyboard shortcuts that make selecting entire rows and columns in Excel a piece of cake.
Here I have a basic table in my spreadsheet:
I clicked into cell A3 and pressed SHIFT + SPACE. Row 3 was highlighted to the end of the table row:
I again clicked into cell A3 and pressed CTRL + SPACE (^ + SPACE on a Mac). Column A was highlighted to the end of the table column:
This certainly beats my former technique of dragging the cursor around.