If I understand the question correctly, you should be able to simply copy/paste the people from your Excel sheet into the people column of your Events table.
Where the people names in your Excel sheet match existing records in your People table, the paste will complete the link. Where there’s no match, you’ll get a blank.
I suggest creating a temporary text field to the right of your people field in the Events table. Paste everything in there first; then paste again in your people field. Where you see blanks, then you just copy from right to left and create a new linked record.