The KB4462177 security update mainly patches up security hole in Microsoft Office 2010. It is meant for standalone version of Office 2010 only, not for Click-to-run edition or Office 365 Home.
What does it do?
There is a vulnerability in Microsoft Excel (CVE-2019-0669) which could be exploited to disclose contents of memory. The attacker could create a special malicious document and persuade victim to open it. This update changes how Excel handles objects in memory.
It also prepares your software to enable the new era in Japanese calendar.
Do I need it?
Since it fixes known and exploitable vulnerability, yes, I would install it as soon as possible.