arrow lines in table

[Raymond]

Using OS X, PowerPoint X for Mac

I have created a slide with a table (4 columns across, 3 rows down). I
moved the slide to another location in the presentation and then tabbed to
create 3 more rows at the bottom. This created arrow points on the right
end of the lines on the bottom of the newly created cells.

"Insert Cells" creates cells with the same problem.

Anyone know why and how I can get rid of the arrow points?

Thanks in advance.

Raymond