Is there a way I can refresh only new data?
Short answer: yes, either using a DB Output + Input block in Live query mode, or a Storage Block.
Is your source a Database Table and the data already being appended and written to a table?
In this case you could set up a Database Source block in Live query mode directly connected to a Report block
with the Data change detection in auto-refresh or auto-detect mode
This way you report will always show the fresh data, and you could also control what data to display by setting a custom query.
For example deciding to show always the most recent window of data
Otherwise, for incremental loading of data coming from different sources, you can use a Storage block in append mode, so to write new data to the same Storage table, and use the same Storage Table as input of a Report to visualise old + new data, always the latest version.
Data is queryable by the time the is written / appended. N.B. the Storage block is shared with all projects on the installations