Q. What is currently considered an "alternative periodic table"

        Details of answer;
      Alternate forms of the grid-like flat periodic table have long been proposed – short form, extra long form, left step, right step, etc. Eminently more practical to work with, the flat grid idea itself is an alternative to the first true periodic table, a three dimensional helical arrangement, de Chancourtios'. Today's standard is called the "long form".
      Alternative periodic tables are developed often to highlight or emphasize different chemical or physical properties of the elements, which are not as apparent in traditional periodic tables. Some tables aim to emphasize both the nucleon and electronic structure of atoms. This can be done by changing the spatial relationship or representation each element has with respect to another element in the table. other tables aim to emphasize the chemical element isolations by humans over time.
      IUPAC, the organization that determines the approved periodic table, is the world authority on chemical nomenclature, terminology, standardized methods for measurement, atomic weights and other critically evaluated data.
      Other tables have been developed by Roy Alexander, Theodor Benfey, George Gamow, Hinsdale Bernard, Paul Giguere, Glenn Seaborg, Timmothy Stowe, and many others. Some have been patented, some 2-D, some 3-D, and R.L.Rich proposes a periodic table where elements appear more than once when appropriate.

        Resources;
chemistryexplained.com, meta-synThesis.com, .chem.ox.ac.uk, Wikipedia