You can merge or split cells using the Merge cells and
Split cell buttons on the Home tab, in the Table group. You can also use the corresponding items in the context menu.
Merge cells
When merging, only the data from the top left cell of the range is saved in the new cell. Data from all other cells will be deleted.
To merge cells, select the cells, then use one of the methods:
–Click the Merge cells button.
–From the context menu, select Merge cells.
–Press the keyboard shortcut Alt+Ctrl+M (Option+Cmd+M).
Split cells
You can split a previously merged cell as well as a regular cell.
When you split a previously merged cell, it is split into the original number of rows and columns. The data from the merged cell will be placed in the upper left cell of the new range, the other cells will be empty.
To split a cell, select the cell, then use one of the methods:
–Click the Split cell button.
–From the context menu, select Split cell.
–Press the keyboard shortcut Alt+Shift+M (Option+Shift+M).