Workbooks provide a flexible canvas for data analysis and the creation of rich visual reports within the Azure portal. They allow you to tap into multiple data sources from across Azure and combine them into unified interactive experiences. Workbooks let you combine multiple kinds of visualizations and analyses, making them great for freeform exploration.
Workbooks combine text, log queries, metrics, and parameters into rich interactive reports.
Workbooks are helpful for scenarios such as:
Exploring the usage of your virtual machine when you don't know the metrics of interest in advance. You can discover metrics for CPU utilization, disk space, memory, and network dependencies. Explaining to your team how a recently provisioned VM is performing. You can show metrics for key counters and other log events. Sharing the results of a resizing experiment of your VM with other members of your team. You can explain the goals for the experiment with text. Then you can show each usage metric and the analytics queries used to evaluate the experiment, along with clear call-outs for whether each metric was above or below target. Reporting the impact of an outage on the usage of your VM. You can combine data, text explanation, and a discussion of next steps to prevent outages in the future.
Source : https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-overview