Recently I have installed the package kubuntu-desktop. Then I came to know that there is anotheer similiar package kde-standard which will install the following new packages:
accountwizard akonadi-backend-mysql akonadi-server akregator dragonplayer juk
kaddressbook kde-baseapps kde-config-mailtransport kde-plasma-desktop kde-standard
kdepim-addons kdepim-runtime kdepim-themeeditors kf5-kdepim-apps-libs-data
kf5-messagelib-data kio-ldap kio-sieve kmail kmailtransport-akonadi knotes kopete
kopete-data korganizer ktnef kwrite libbctoolbox1 libbzrtp0 libgadu3
libgrantlee-textdocument5 libkf5akonadi-data libkf5akonadiagentbase5
libkf5akonadicalendar-data libkf5akonadicalendar5abi2 libkf5akonadicontact-data
libkf5akonadicontact5abi1 libkf5akonadicore-bin libkf5akonadicore5abi2
libkf5akonadimime-data libkf5akonadimime5 libkf5akonadinotes-data
libkf5akonadinotes5 libkf5akonadiprivate5abi2 libkf5akonadisearch-bin
libkf5akonadisearch-data libkf5akonadisearch-plugins libkf5akonadisearchcore5
libkf5akonadisearchdebug5 libkf5akonadisearchpim5 libkf5akonadisearchxapian5
libkf5akonadiwidgets5abi1 libkf5alarmcalendar-data libkf5alarmcalendar5abi2
libkf5calendarcore5abi2 libkf5calendarsupport-data libkf5calendarsupport5abi1
libkf5calendarutils-bin libkf5calendarutils-data libkf5calendarutils5abi1
libkf5contacteditor5 libkf5eventviews-data libkf5eventviews5abi1
libkf5followupreminder5 libkf5grantleetheme-data libkf5grantleetheme-plugins
libkf5grantleetheme5 libkf5gravatar-data libkf5gravatar5abi2
libkf5identitymanagement-data libkf5identitymanagement5abi1 libkf5imap-data
libkf5imap5 libkf5incidenceeditor-bin libkf5incidenceeditor-data
libkf5incidenceeditor5abi2 libkf5kaddressbookgrantlee5
libkf5kaddressbookimportexport5 libkf5kdepimdbusinterfaces5 libkf5kmanagesieve5
libkf5kontactinterface-data libkf5kontactinterface5 libkf5ksieve-data libkf5ksieve5
libkf5ksieveui5 libkf5ldap-data libkf5ldap5abi1 libkf5libkdepim-data
libkf5libkdepim-plugins libkf5libkdepim5abi2 libkf5libkdepimakonadi5
libkf5libkleo5abi1 libkf5mailcommon-plugins libkf5mailcommon5abi4
libkf5mailimporter-data libkf5mailimporter5abi1 libkf5mailimporterakonadi5
libkf5mailtransport-data libkf5mailtransport5abi2 libkf5mailtransportakonadi5
libkf5mbox5 libkf5messagecomposer5abi2 libkf5messagecore5abi2 libkf5messagelist5abi1
libkf5messageviewer-plugins libkf5messageviewer5abi5 libkf5mime-data libkf5mime5abi2
libkf5mimetreeparser5abi3 libkf5pimcommon-plugins libkf5pimcommon5abi3
libkf5pimcommonakonadi5 libkf5pimtextedit-data libkf5pimtextedit5abi3
libkf5sendlater5 libkf5templateparser5abi2 libkf5tnef-data libkf5tnef5
libkf5webengineviewer5abi3 libkgantt2 libkgantt2-l10n libkolabxml1v5 libkopete1
libkpimgapi-data libkpimgapicalendar5 libkpimgapicontacts5 libkpimgapicore5abi1
libkpimgapitasks5 libkpimimportwizard5 libkpimitinerary-data libkpimitinerary5
libkpimkdav-data libkpimkdav5abi2 libkpimpkpass5 libkpimsmtp5abi1
libmediastreamer-base10 libmediastreamer-voip10 libortp13 libotr5 libprotobuf-c1
libqgpgme7 libqt5networkauth5 libsasl2-modules-kdexoauth2 libturbojpeg
libxerces-c3.2 libzxingcore1 mariadb-client-core-10.3 mariadb-common
mariadb-server-core-10.3 mbox-importer pim-data-exporter pim-sieve-editor sweeper
Do I really need these packages to have a smooth KDE Plasma experience on Ubuntu?
Most of these are KDE PIM applications (akregator, kaddressbook, kmail, korganizer) and their dependencies. There are some other KDE apps (juk, dragonplayer, kwrite) in there as well. None of them are essential for running the Plasma desktop though