There is no plural form for "inlaid" because it describes a state or condition, not a countable object.
For example:
* Incorrect: "The table had many inlaids."
* Correct: "The table had many inlaid designs."
To refer to multiple inlaid objects, you would say something like:
* "The table had many inlaid pieces of wood."
* "The cabinet featured several inlaid panels."