If you want to go from Zotero to Excel, use the CSV export in Zotero. Getting data from Excel to Zotero is significantly harder -- what exact format are they in?
I entered the manuscript data into Excel columns It is a large number of data, and it is difficult to rewrite each reference again in Zotero It is stored as an excel file
As Zotero cannot guess how you have constructed the Excel sheet, and so does not know exactly what your Excel columns contain, this won't be a matter of simply importing.
Have a look at the fields in a Zotero entry (Item Type, Title, Author [possibly multiple authors], Abstract, Publication, Volume, Issue, Pages, etc etc) and try to work out for your self how exactly they map onto the columns in your Excel sheet. You will likely find there is no clean one-to-one mapping, which means an importer would run into problems.
Depending on how your Excel sheet is laid out, your best bet may be to copy everything, paste it into a text file, and feed that file into text2bib. That would then give you a .bib formatted file that can be imported by Zotero. However, the result will only be as good as the input data.
Thanks for the clarification, and this leads me to ask about another topic that might solve the problem, and my question is, can I increase the number of cells in Zotero if I choose to enter a script? So that I can increase the boxes I need?
If you don't have excellent scripting skills this may be a very time-consuming trial and error process. Even then, your import may be error-prone. Any errors you made hand entering your material into Excel will be transferred to your Zotero database.
There may be an easy way to get the records into Zoteo if you have mostly journal articles (or if you have books that have an ISBN) in your spreadsheet if you have only a few hundred Excel records (rows). If you have thousands of items in your Excel database my idea is not so good for you.
If your journal articles have DOI numbers you can use the Zotero magic wand tool to quickly add metadata to the Zotero database. A better idea might be to use the DOI number to access the article on the publishers' websites. That way you will get good metadata and you will also get the abstract from the publisher. (The Zotero magic wand tool doesn't capture the abstract.)
If you don't have DOI numbers, I suggest copying the article titles one-by-one into a Google Scholar search and following the GS link to the publisher's site and using the Zotero download button to capture the metadata and abstract.
This may seem like a tremendous amount of effort but the advantage is that you will have accurate metadata.
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My question is wrong, I want the opposite
I have data in Excel and want to convert it to Zotero
It is a large number of data, and it is difficult to rewrite each reference again in Zotero
It is stored as an excel file
Have a look at the fields in a Zotero entry (Item Type, Title, Author [possibly multiple authors], Abstract, Publication, Volume, Issue, Pages, etc etc) and try to work out for your self how exactly they map onto the columns in your Excel sheet. You will likely find there is no clean one-to-one mapping, which means an importer would run into problems.
Depending on how your Excel sheet is laid out, your best bet may be to copy everything, paste it into a text file, and feed that file into text2bib. That would then give you a .bib formatted file that can be imported by Zotero. However, the result will only be as good as the input data.
There may be an easy way to get the records into Zoteo if you have mostly journal articles (or if you have books that have an ISBN) in your spreadsheet if you have only a few hundred Excel records (rows). If you have thousands of items in your Excel database my idea is not so good for you.
If your journal articles have DOI numbers you can use the Zotero magic wand tool to quickly add metadata to the Zotero database. A better idea might be to use the DOI number to access the article on the publishers' websites. That way you will get good metadata and you will also get the abstract from the publisher. (The Zotero magic wand tool doesn't capture the abstract.)
If you don't have DOI numbers, I suggest copying the article titles one-by-one into a Google Scholar search and following the GS link to the publisher's site and using the Zotero download button to capture the metadata and abstract.
This may seem like a tremendous amount of effort but the advantage is that you will have accurate metadata.