When using a DataTable based on a structure that includes TArray or TMap, if a row is not selected, the memory usage will continue to increase.
This is because in SDetailsViewBase::Tick, ForceRefresh() is called continuously due to Result == EPropertyDataValidationResult::ObjectInvalid.
To solve this issue, you can stop the Tick of the DetailView when it is not selected, as shown in the following code.
result : memory usage keeps increasing
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-183526 in the post.