Excel Keymap provides the following set of key for navigation in grid:
Enter + Ctrl - disables cell editor, there is no moving to any cell;
Enter+Shift - disables cell editor, selects cell located up relative to the current one;
Enter - disables cell editor, selects cell located down relative to the current one;
Tab - disables cell editor, selects the next right cell;
Tab+Shift - disables cell editor, selects the previous left cell;
F2 - enables cell editor;
ESC - disables cell editor, input value is not saved;
PgUp - moves to the previous page;
PgDow - moves to the next page;
Left-Arrow - selects the left cell;
Right-Arrow - selects the right cell;
Up-Arrow - selects the cell up;
Down-Arrow - selects the cell down;
Ctrl + Left-Arrow - selects the first cell in the string;
Ctrl + Right-Arrow - selects the last cell in the string;
Ctrl + Up-Arrow - selects the first cell in the column;
Ctrl + Down-Arrow - selects the last cell in the column;
Shift + Up-Arrow, Shift + Down-Arrow - massive strings selection;
Ctrl + Shift + Down-Arrow - selects all the strings from the current one to the last one;
Ctrl + Shift + Up-Arrow - selects all the strings from the current one to the first one;
Home - selects the first cell in the current string;
End - select the last cell in the current string;
Ctrl + Home - selects the first cell in grid (at the top on the left);
Ctrl + End - selects the last cell in grid (at the foot on the right).
Note: In case cell is selected and it is editable, when starting typing cell editor opens and allows to input data.