Information from How to Apply Thermal Interface Material (TIM).
Is there a specific amount of Thermal Paste recommended when reseating the Intel® Xeon® Scalable Processors?
The thermal paste comes already attached to the heatsink (see Installing an LGA3647 Socket on Intel® Xeon® Processors). Therefore, there is no need to apply any to the processor. However, in the event the original thermal paste was either removed by accident or for maintenance purposes, the content in the pillow pack is what should be applied, entirely, right to the center of the chip.
For more detailed information, refer to the How to apply TIM section of the How to Apply Thermal Interface Material (TIM) article.