Good idea! We have something similar.

We have a "Preferences" table with one record and one form. The Preferences table opens to a form, not a table. There is a Choice field named "Startup Table" on the form that allows the user to select which table to display automatically at time of database startup. A script similar to the following was added to the Options/"Trigger after open" property ("Options" is located beside "Data Model" at startup in design mode):

let v := text(record('Preferences',1).'Startup Table');
if v = "Contacts" then
  openTable(v, "Contacts");
  popupRecord(record(Contacts,1))
else
  if v = "Transactions" then
    openTable(v, "Transactions");
    popupRecord(record(Transactions,1))
  else
    if v = "Invoices" then
       openTable(v, "Invoices");
       popupRecord(record(Invoices,1))
    end
  end
end

CAUTION: Make sure that the Choice popup field has a "None" item, in addition to a item for each table name. Otherwise, you might lock yourself out of the default database home page. It is best that you backup your solution before you try this.