Use the Combine Columns function to combine the text of two columns:

To combine columns in Gigasheet, click Tools > Columns > Combine Columns. Next, select two or more columns to combine into a new concatenated column. To add columns, simply select the “+” sign to the right of the column title. Once you have selected the columns you wish to combine, input your separator. This can be whatever value you want. Lastly, input your new columns name and hit “Apply”.

Looking to add the values of two numeric columns? Check out Arithmetic

Combine Columns Video