In Excel, you can merge two columns of data into one column using a simple formula or a built-in feature called "Concatenate." Here are two methods to achieve this:

1. **Using the Concatenate Function**:

- Suppose you have data in columns A and B, and you want to merge them into column C.

- In cell C1 (or any empty cell where you want to start the merged data), enter the following formula:

```

=CONCATENATE(A1, " ", B1)

```

This formula concatenates the values in cells A1 and B1 with a space between them.

- Press Enter to apply the formula. Cell C1 will now display the merged data from columns A and B.

- Drag the fill handle (the small square at the bottom-right corner of the cell) down to fill the formula for all rows where you want to merge the data.

2. **Using the Ampersand Operator (&)**:

- Alternatively, you can use the ampersand (&) operator to concatenate values.

- In cell C1, enter the following formula:

```

=A1 & " " & B1

```

This formula achieves the same result as the CONCATENATE function by concatenating the values in cells A1 and B1 with a space between them.

- Press Enter to apply the formula, and then drag the fill handle down to fill the formula for all rows where you want to merge the data.

Both methods will merge the data from columns A and B into column C. You can adjust the formula as needed, such as adding different delimiters or formatting options. Remember to be cautious when merging data, as it may affect the original data structure and could potentially lead to data loss if not done carefully.