Combining Ctrl + Shift + Arrow keys lets you extend your selection in any direction until Excel hits a blank cell. Start from the top-left corner of your data, try Ctrl + Shift + Right Arrow, then ...
If you want to give it a try, it’s available in two formats — standard for one-hand typing and wide for two-hand typing — in ...
You can buy all kinds of keyboards these days, from basic big-brand stuff to obscure mechanical delicacies from small-time builders. Or, you can go the maker route, and build your own.