1. Type text into a cell.
2. Select the cell and few more cells in the same row.
3. Select Home -> Merge & Center (in Alignment Group).
Or
Click the dialog box Launcher arrow symbol in the bottom-right corner of the Alignment Group to open the Format Cells dialog box -> Alignment tab.
Or
Press Ctrl+1.
4. In the Alignment tab in Text control section check the Merge cells box and click OK.