Either use a server side workflow, or use the Glide API.
If the source table is a Big Table, then you can either use a server side workflow, or the Glide API.
For a regular Glide table, you can build a query or relation to match the rows you want deleted, then use a Delete Row action, targeted at the query/relation.
Mainly (as @Darren_Murphy mentions), relate/query to rows you wish to delete, and in workflows use “Data”–>”Delete row” –> Select query.
API only lets you delete one row at the time (both normal- and big-tables).
If you are using big tables, API v2 has PUT {"rows": []}, to delete all rows / clear table.
Bulk edits
No real “good” options. If you expect to edit <10 rows at the time, you can create a table that relates to rows you wish to edit. (Column 1 = Relate 1, Column 2 = Relate 2…) And then in workflow set up “Data” –> “Set column values” for each Relate.
API only lets you edit one row at the time (both normal- and big-tables).
Bulk Add
Here big tables / API v2 lets you add multible rows with one call via stash.
Just to clarify - that’s true, but you can send up to 500 mutations (adds and/or edits) in a single API call. But each mutation still counts as an update.