power point means a strong point of view. Presentation is not because of PowerPoint, but because the main purpose of this software is to help people make a better presentation (Chinese translation is "presentation"), so the file generated by it is named "presentation". Over time, this thing is often called ppt or slide show in China. In fact, Americans don't call their presentations ppt, but "slice".
excel is office software, which means to surpass. But in China, we call it "table" according to the purpose.