If your theme is Online Store 2.0 compatible, you can change your discount table position using the following method.
How to know if your theme is Online Store 2.0 compatible?
During the onboarding page, select the Check if theme is Store 2.0 button.
If the status shows Online Store 2.0 Detected:
Your theme is Online Store 2.0. Each time you change your theme, this is a compulsory step for you to setup. To access this page if you had already done the onboarding, please go to the Install page on the navigation bar.
Changing Discount Table Position on Product Page
First, go to Themes page in Shopify Admin Panel. Select the Customize button.
Select the Products > Default Products the the page navigator located at the middle of the screen:
Next, select Add block at the sidebar and proceed to select Discount Table (Quantity Breaks & Discount).
Once Discount Table is added, you can customize where you would like the discount table to be displayed by dragging and dropping the block:
Select Save to complete this process: