Yes, to apply shading to multiple columns at once, select the range of cells you want to apply the shading to in all the columns you want, including the column headings if required. Then, go to the Home tab, click on Conditional Formatting, and select New Rule. In the New Formatting Rule dialog box, select 'Use a formula to determine which cells to format' and enter the formula 'MOD(ROW(),2)=0'. Finally, select the formatting you want to apply to the shaded cells and click OK.