I know that I can draw a table in Word or Excel and take a screenshot. I just want to ask if there is any direct way to do that.
Your particular use case is too rarely needed to find any special software to automate the entire process of converting a table to an image. In fact, the top three results for a web search of "table to image" give instructions that are going to take you longer than taking a screenshot and saving it as an image.
However, you can speed up part of the process by using a screenshot software. I recommend Greenshot.
Mac OS X already provides several screenshot shortcuts. You can use Cmd+Shift+4 then select an area to get the same effect. The image will be saved to your desktop.
You must configure Greenshot to automatically save screenshots to a particular location.
After the configuration, simply press the Print Screen key on your keyboard, then draw a box around the table. Greenshot will create the image file automatically.
If the next table is fitting the same exact region (the box you drew), you can screenshot it even faster with Shift+Print Screen.
You can also change the various keyboard shortcuts to your liking in the General tab.
Greenshot can also upload the image automatically to Dropbox or Imgur.