The completely rational way to combine two cells in a Word 2016 table into one or to split one cell into two is to use the table drawing tools. Heaven have mercy on you should you decide to merge or split cells in any other fashion.
To combine two cells, erase the line that separates them. Follow these steps:
Click the Table Tools Layout tab.
In the Draw group, click the Eraser tool.
The mouse pointer changes to a bar of soap, shown here, but it's supposed to be an eraser.
Click the line between the two cells.
The line is gone.
Click the Eraser tool again to quit merging.
Or you can tap the Esc key.
To merge a clutch of cells, select them and click the Merge Cells button. That button is found on the Table Tools Layout tab, in the Merge group.
