Text boxes in Excel 2013 and 2010 provide a way to add large blocks of text atop a spreadsheet. When you write in a text box, the text can contain multiple styles, fonts, colors and line breaks, just as if you were typing in a Word document. Text boxes also don't adjust the formatting of your spreadsheet, so you could use a box to display a large font without enlarging a row of cells.
Open the drop-down menu below "Text Box" in the Text section of the Insert tab and pick either a horizontal or vertical text box. The orientation affects the direction of the text inside the box, not the box's shape.
Click and drag on the spreadsheet to draw the outline of the text box. Release the mouse button to place the box.
Type to fill in the text box. When you finish, click outside the box to return to editing cells. To edit the text later, click inside the box.
Switch to the "Format" tab with the text box selected and click "Edit Shape" and then "Change Shape" to alter the text box's outline. Changing the shape does not reflow text to fit the outline: Text in Excel text boxes remains rectangular regardless of the box shape.
Drag the handles around the text box to resize the box. To rotate the box and its contents, drag the rotation handle above the box.
Select style options on the Format tab to redesign the text box. For example, choose a border color from the Shape Styles section, a text color with the "Text Fill" button and box shading from the "Shape Effects" button.