Turn something you pasted back into a table

Data that has been through a PDF has usually been through a shredder. What was a table becomes lines of text with the column boundaries implied by spacing, page headers repeating every forty rows, and totals sitting in the middle of the data as though they were data. Copying it into a spreadsheet produces one long column and a bad afternoon.

The useful trick is to stop thinking of it as a formatting problem and start thinking of it as a detection problem. The columns are still there, they are just described by whitespace instead of delimiters. Detect the boundaries once, apply them to every row, and then the only remaining work is deciding which rows were never data in the first place.

That second half is where judgement lives, and it is the part worth checking rather than trusting. Repeated page headers are obvious. A subtotal row that looks exactly like a data row apart from a bold that did not survive the copy is not, and if it slips through it will quietly inflate whatever you calculate next. Look at the row count before and after, and if the difference does not match what you expected to be removed, look at what went.

This matters more than it sounds because pasted data usually skips validation. A CSV export from a system has been through that system's rules. A table copied out of a supplier's PDF has been through nothing at all, and it is going straight into your spreadsheet, or worse, straight into an import. Treat it as untrusted input, because that is exactly what it is.

Everything happens in this page, which is the practical reason to use it rather than a server-side converter. Pasted tables are very often commercial: a rate card, an invoice breakdown, a customer list a client sent over. Those are not files to hand to a free web service in exchange for a CSV.

If this is a monthly job against the same supplier's PDF, the honest answer is that somebody should be sending you the data rather than a document. That is usually a conversation rather than a technical problem, and it is a conversation worth having, because the applet will keep working and the underlying waste will keep happening.