Ctrl + A observation (not a question)

I made an interesting observation. I don't know if it's because I'm using the web version of Excel, but I noticed that when I select a cell in a group of cells with text, Gross Sales Income for example, and use Ctrl + A, it only selects the cells in that group (Gross Sales Income, Discounts, Net Sales, Cost of Goods Sold, Gross Profit, Distribution, Warehousing, and Full Delivered Margin) and not the whole sheet. When I select a blank cell and use this shortcut it selects all cells.