Console Utility iMac
Yes, this is completely normal behavior. Here is an example of how to break down the messages in the console app.

This is my what appears when I open my console app.



Look how many messages came in within a second at 14:03:04! That's a lot of data to process! But you don't have to process this data.

Let's say you're looking for an error message, click on the box in the top left labelled Errors and Faults. This is what mine looks like.



Less than an error per second. Much easier to process. But my guess is that even this is not what you were looking for. Check out the sidebar here:



These are the various files and folders that contain various logs for both built-in and third party apps. If you click on one of these files or navigate through the folders to the log file you are looking for you can view the log file in app. My guess is the what you are looking for is the system.log which records information for built-in system functions. 

This is an example of what an open system.log file looks like.