"Yes, I will book a time slot for this test." is the best choice.

If you'd like a more natural or professional phrasing, here are a few options:

Option 1 (simple):

Yes, I will book a time slot for this test.

Option 2 (professional):

Yes, I will schedule a time slot for this test.

Option 3 (slightly formal):

Yes, I will arrange a suitable time slot for this test.

Improvements

• Word choice: "time slot" is more commonly used than "time slice" when referring to a scheduled period of time.
• Clarity: "schedule" or "arrange" sounds more natural in business communication than "book" in some contexts.

For most workplace communications, "Yes, I will book a time slot for this test." is the best choice.