Hi Jamie Davis,
As per my knowledge the "Task" Event loaded around 42 seconds is the total time you have recorded the performance from stating to end time. Please go through the below URL's will give you more information.
Can you post that workbook.
Basically Use performance workbooks to analyze and troubleshoot performance issues pertaining to different events that are known to affect performance, including:
Connections to data sources
Server blending (Tableau Server only)