RELATED IDEAS
Pressing "up" should move the cursor to the cell above within a table
Imagine a table (or use the one below):
Top left |
Top right |
Bottom left |
Bottom right |
In Firefox (and possibly other browsers), using the up arrow in one of the bottom cells, brings the cursor to the beginning of the line of the current cell instead of moving the cursor to the corresponding top cell.
likewise either tab or right/left arrows should allow a user to navigate through a custom table