Select the cell or cells you want to make bigger
Increase the row height by dragging the row boundary downward
Increase the column width by dragging the column boundary to the right
Use Home > Format > Row Height to set a specific row height
Use Home > Format > Column Width to set a specific column width
Merge multiple cells to create one larger cell
Use Home > Merge & Center to merge selected cells
Adjust font size to make the cell appear larger
Turn on Wrap Text if the content needs more space inside the cell
Double-click the row or column boundary to AutoFit the size to the content