121) The need
122) Proofreading, bulk word changes, or splitting the job between several people — all of that moves much faster in a sheet than in plain text. SRT itself is plain text, but its cue structure (index, timing, dialogue) maps neatly onto four spreadsheet columns.
123) Where to do it
124) Open Subtitle ⇄ table conversion, switch to "to table", drag in the SRT, and the preview fills with one row per cue across four columns — index, start, end, text. Hit "Download Excel (.xlsx)" and it is yours. VTT is supported the same way.
125) When you are done editing: switch the mode to "to subtitle", put the sheet back in, and you get an SRT again. The rule is three columns for start, end and text (English Start / End / Text work too), in any order.
128) Common pitfalls
129) Fix broken encoding first: this page reads UTF-8 only. A screenful of question marks or boxes means a trip to Mojibake repair first.
130) CSV or xlsx: choose .xlsx when the file is going into Excel, so the time column cannot be reformatted; CSV is more portable but Excel may read it as something else — set the time column to "Text" if that happens.
131) ASS does not work: ASS carries style directives, so convert it to SRT before putting it in a table.
132) Related
133) The full two-way walkthrough — How to convert subtitles to Excel / CSV; translating afterwards — Subtitle translation; a last pass before delivery — Subtitle QC.