Yes. In most corporate setups you can keep a traveller profile for each employee of a company account, and the details you already hold are filled in automatically the next time anyone books for that person.
A profile normally holds the things that rarely change, such as the name as it appears on the passport, date of birth, passport number and expiry date, contact details, frequent flyer and hotel loyalty numbers, meal or seat preference, and the department or cost centre the person belongs to. When your staff or the company's own travel booker starts a booking for that traveller, those fields come through instead of being typed again. That saves time on repeat trips and cuts down on misspelt names, which are one of the most common reasons a ticket has to be corrected later.
Be aware that what the system can store and what the supplier will actually accept are two different things. Loyalty numbers and meal requests are usually passed through, a seat preference is often only a request rather than a guarantee, and some suppliers want certain details only at the ticketing stage or ignore fields they do not support. Whether the company admin can edit their own employees' profiles, or whether only your team can, depends on how your plan and your permission settings are arranged. You are also holding sensitive personal data, so keep access limited and keep only what you genuinely need under the rules that apply where you operate.
Before you load a client's staff list, check which profile fields your main airline and hotel suppliers accept, and agree with the client who on their side is allowed to add or change traveller details.