Problem
I seem that, you cannot display the table header in an every page of a SSRS report, even if you check the Repeat header columns on each page option in the Tablix properties (to open the table properties in Report Builder, right click on that specific table, and choose Tablix Properties).
Solution
To solve this, follow the below steps:
Make sure you check the Repeat header columns on each page option in the Tablix properties.
Go to the Grouping pane (the bottom section of the report), click the small arrow from the upper-right corner, and click Advance (the static properties are now displayed).
...
Check to view the Properties windows from View tab and click on the first static property of the Row Group.
In the Properties dialog box, in Other section, set the KeepWithGroup property to After and RepeatOnNewPage property to True.