Update a table but only few rows

I have 2 tables. Table1 with 4000 rows and 6 columns.
Table 2 has 100 rows and same 6 columns. Table 2 is more recent. I want to update this in Table 1. But the 100 rows are scattered in Table 1. How do I copy Table 2 into Table 1 without affecting the other 3900 rows of Table 1.

I dont want to use VBA. Is there any simpler way?

Regards,
Vaibhav