Table name such as &1 is invalid; removed from selection -> long text

What causes this issue?

The name of the table or view either
contains invalid character(s) or
its length is invalid or
it contains lowercase character(s).

System Response

Invalid names of tables and views are automatically removed from the
selection.

How to fix this error?

Table/view names that contain invalid characters such as @ # $ % are not
supported. Furthermore, a maximum of 30 characters is allowed in table
names. Lowercase characters are not supported.
If the name of the table/view you selected is not supported, create a
new valid name for the table/view.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.