This is potentially dangerous if you open a workbook that contains a virus (in the form of a macro built for malicious purposes). Doing this enables all macros to run in any workbook that you open.
For a more thorough understanding of macro security in Excel, we recommend reading the following topic on the Microsoft Office website: This article is not intended to provide complete information on the topic of Excel macro security or to provide a definitive answer for your specific security needs. This may disable certain functionality of the workbook. It includes Classic Menu for Word, Excel, PowerPoint, Access and Outlook 2007.When opening an Excel workbook or creating a new workbook from a template, macros may be disabled depending on your macro security settings in Excel. It includes Classic Menu for Word, Excel, PowerPoint, OneNote, Outlook, Publisher, Access, InfoPath, Visio and Project 2010, 2013, 2016, 2019 and 365. Supports all languages, and all new commands of 2007, 2010, 2013, 2016, 2019 and 365 have been added into the classic interface. You can use Office 2007/2010/2013/2016 immediately without any training. As a result, you wont see the Security Warning again when you open this specific Excel file in the future. Note: by clicking Enable Content, the Excel file becomes a trusted document. When the message bar appears, click Enable Content to enable macros.