Set minimum size for tabwidget
MODIFY
src/mainwindow.ui
src/mainwindow.ui
<property name="enabled">
<bool>true</bool>
</property>
+ <property name="minimumSize">
+ <size>
+ <width>0</width>
+ <height>500</height>
+ </size>
+ </property>
<property name="currentIndex">
<number>0</number>
</property>

Set minimum size for tabwidget