Open your Excel workbook
Select the row or cell where you want to add a line
Go to the Home tab
Click Borders in the Font group
Choose the border style you want
Select Bottom Border, Top Border, or All Borders
Use the Draw Border tool for custom lines
Drag across cells to draw the line
To add a line chart, select your data
Go to the Insert tab
Click Line Chart
Choose the line chart style
To insert a line break in a cell, double-click the cell
Place the cursor where you want the break
Press Alt + Enter on Windows
Press Control + Option + Return on Mac